Activities

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BELOW IS A COLLECTION OF SCIENCE ACTIVITIES SUITABLE FOR CHILDREN (and adults who have not done them before!)

       OLYMPUS DIGITAL CAMERA        oldworldkite_1

 Paper Easy-to-Fly Kite

Source:  Dorothy Norton

1.  Basic Kite form:

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a.  Using an 8.5 inch by 11 inch piece of paper, draw center fold line A on the front of the form along the center line as shown.  Then draw sloped fold lines B and C such that the top of each line is 0.5 inch from line A and the bottom is 2.0 inches from line A.  Also mark two punch holes–one half way between lines A and B and one between lines A and C–3.5 inches from the top of the form. 

b.  On the back side of the form, draw the straw lines as shown.  The outer ends of the line are 1.25 inches from the top edge.  When the fold is made, the fold line will appear straight and go from one edge of the back to the other.  Use black pen or pencil rather than marker to make the lines.  (Marker would soak through and be visible on  both sides.) 

c.   If you want the kite to show a design (e.g. the Welsh flag as shown at the top of the page), divide the picture–a line drawing such as the dragon shown–in half and paste the left edge of the right half along line B and the right side of the left half along line C.  When the center flap is folded, the picture will come back together again (as in the Welsh flag kite above).  Once the form is made, it can be copied with a copy machine.

2.  Creating the kite:

Safety considerations:  Never fly kite near power lines or near a street.  An open field–or even a very large open room–works well.

Materials needed for each kite:
kite form with or without design (on front) copied onto 8.5 X 11 inch sheet of paper
clear tape
plastic straw 8 to 9 inches long (recycled McDonald’s straw works very well)
3 paper streamers or strips of colored paper, newspaper, etc. about 1.5 X 24 inches)
spool of sewing thread

Equipment:
paper punch
markers or crayons to color design

a. Color design and let dry.  Then fold along line A so that back sides are together.  Then fold up along lines B and C to form vertical front support flap.
b.  Turn to back and tape flap in place using three horizontal tape strips:  one at top, one in middle, and one at the bottom.
c.  Tape straw in place, centered along straw guideline as shown below:

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Again, use three strips of tape long enough to tape down the straw without flattening it:  one at left edge, one at right, and one in the center.
d.  Tape streamers in place.  They may be attached as shown above–one right, one left, and one centered–or all three at the center of the bottom edge.
e.  Reinforce the punch hole on the front with tape before punching  a hole there with a paper punch.
f.  Tie sewing thread to the kite at the hole using a square knot.  The thread serves as the kite string.

You are ready to fly the kite, but wait for a dry day.  (Once the kite becomes wet, it will not fly well. )  This kite flies so easily that a runner can get it to go up by running, even inside a building.  Be careful and have fun!  

Shoe Traction Investigation

Basic concept: Traction (avoiding slipping) depends on the characteristics of surfaces in contact. Because surface details can be complicated whenever any form of frictional force is involved, a parameter called the coefficient of static friction is used. It can be show to be equal to the tangent of the angle (technically referred to as the Angle of Repose) at which one material slides over another when the second surface is sloped. The larger the angle, the larger the tangent of the angle is and the greater the coefficient. Larger coefficient means that there it is less probable that the object will slip and better traction is expected.

Learning Objectives:

Concepts: Friction is a force that prevents (or slows down) the sliding of one object over another. It can be described in terms of a number that can be used to compare pairs of surfaces.

Skills: Measuring angles, use of Excel or calculator

Safety considerations: For hygiene purposes, each person should probably handle only his or her own shoes. While shoes are off, there should be no running.

Materials: Shoes, long wide board or other solid surface, protractors, calculators or computers with Excel spreadsheet set up to calculate coefficients.

Procedure:

  • Each person removes a shoe.
  • Taking turns, each person places his      or her shoe on the horizontal board.
  • While one end is held in place the      other end is lifted until the shoe just begins to slip.
  • Another person measures the angle.
  • Repeat steps 2-4 several times and compute      an average angle.
  • Using Excel or a calculator, compute      the tangent of the average angle of slip. This number is the coefficient      of static friction for the shoe on the board. Arrange the shoe      list in increasing order or increasing coefficients and compare shoes to      try to understand why some shoes slip more easily than other.

Extensions: Do further investigations using the same shoe but on different surfaces. Wet Ice is a good one to try because this is one of the most slippery surfaces we encounter. A greased surface might be another to try. Have individual groups choose their own traction surface/object pairs to measure.

Wisconsin Standards:

C.4.2 Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations

C.4.4 Use simple science equipment safely and effectively, including rulers, balances, graduated cylinders, hand lenses, thermometers, and computers, to collect data relevant to questions and investigations

C.4.5 Use data they have collected to develop explanations and answer questions generated by investigations

C.4.6 Communicate the results of their investigations in ways their audiences will understand by using charts, graphs, drawings, written descriptions, and various other means, to display their answers

C.4.7 Support their conclusions with logical arguments

D.4.7 Observe and describe physical events involving objects and develop record-keeping systems to follow these events by measuring and describing changes in their properties, including:

  • position relative to      another object
  • motion over time
  • and position due to forces

 Earth’s Surface

Question to investigate: How much of Earth’s surface is land and how much is water?

Learning objectives:
Content: Understand that the surface of the Earth is covered partially by water and partially by land in proportions that can be determined by observation and estimated by the use of an accurate model and sampling techniques.
Process skills: observing globe, adding, computing fractions and percentages, catching and throwing, working with model

Method: Sampling of “realistic” model

Subject areas: Mathematics, Geography, Earth Science

Safety considerations: Throw ball in area without breakable objects and avoiding windows. Throw ball gently.

Equipment and supplies: Earth Ball, marker, tape, calculator(s)

Suggested method**:
Have each participant place a bit of tape on a forefinger and mark it with a dot of permanent marker.

Toss the “Earth Ball” around in an outside area or in a large room (without breakable objects). Record on chalkboard, etc. whether the forefinger dot of each catcher was on land or water. To try to get “good statistics”, try to get a large number of catches (100 would be ideal) with each person throwing and catching several times.

Add up total of catches. Compute fraction involving landing on water versus landing on land.
What is the result?
What does that tell us about what fraction of the Earth is covered by water?
Is this a reliable way of determining this information? What method would be more accurate?
**How would you modify this activity to improve it?

Wisconsin Standards:
Science Connections:
A.4.2 ..decide what..models..can be used..

Earth and Space Science:
E.4.3 Develop descriptions of the land and water masses of the earth…

Sink and Float with Fruits and Vegetables

Topic areas: physical science

Equipment and supplies:
tub or bucket filled with water, selection of fruits and vegetables (one or more per person)

Procedure:
Each person should choose a fruit or vegetable. Each then in turn holds up his or her choice so that the group can predict
if it will sink (thumbs down) or float (thumbs up). Then the fruit or vegetable is dropped into the water. Once everyone has had a turn, the group can discuss why objects sink or float in general and why specific items in this set did. This activity can be used to lead into investigation of complex objects (e.g. bananas or oranges) in which the peel may float and the inside float or vice-versa.

Safety: Beware of spilling water on the floor to avoid creating slippery conditions leading to falls. As always objects used for experimentation should not be eaten afterwards. To avoid wasting good vegetables and fruits, however, those which will be cooked or peeled under hygienic conditions after handling may be used rather than thrown away.

Wisconsin Standards:
Science as Inquiry
C.4.2. Use the vocabulary of unifying themes to ask questions about objects, organisms and events being studied.

C.4.5 Use data…collected to develop explanations and answer questions generated by investigations.

C.4.7. Support conclusions with logical arguments.

C.4.8 Ask additional questions that might help focus or further an investigation.

Physical Science
D.4.2. Group or classify objects and substances…

D.4.7 Observe and describe physical events involving objects and develop record-keeping systems to follow these events

 Observations of M & M’s
Dr. Iolo Wyn Williams,
Professor Emeritus, School of Education,
University of Wales Bangor

Materials and equipment:
Water
M & M candies (plain)
Shallow bowl
Paper, markers or colored pencils, pencil or pen

Suggested procedure:
Put about 3 cm. of water in the bowl (enough so that M & M’s will be covered).
Place one each red, blue, yellow candies in the water with m up so that they are not touching each other nor the edges of the bowl.
Observe them. Write down in words and pictures what you observe as time passes.
After sufficient time has passed, share observations with others.
Discuss further possible investigations.
Links to the Standards:
Wisconsin Standard C.4.2: Use science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations.
Wisconsin Standard C.4.8: Ask additional questions that might help focus or further an investigation.
Wisconsin Standard D.4.4: Observe and describe changes in form, temperature, color, speed, and direction of objects and construct explanations for those changes.

Safety Considerations:
M & M’s are designed and sold to be eaten. However, you should adhere strictly to the safety policy that no one should ingest anything that is part of any experiment. Set aside “nonexperimental” M & M’s for eating later.

 M & M Color Distribution: Graph Without Numbers

Materials: M & M’s candies, paper cups, paper towels, pencil, graph paper

Safety Considerations: If investigators handle their own candy it is probably safe to let them eat it at the conclusion of the activity. Be sure that no one involved has an allergy to any of the ingredients, however, before allowing them to eat, however.

Suggested procedure:
1. Before handing out candy, ask the group to predict the color of M&M’s that is a) most common and b) least common. Have each person write down his or her prediction on the back of the graph-paper sheet.
2. Be sure all experimenters have clean hands.
3. Hand out paper towels and small samples of M&M’s in paper cups to each person.
4. Have them sort and count the M&M’s of each color and record the results. Then create graphs by lining up the M&M’s in vertical rows like so:
0
0 0
0 0 0 0
0 0 0 0 0 0
____________

Br R Y O Gr Bl

5. Discuss whether individual results agreed with individual
predictions. Then collect all individual results color by
color, add them, and see whether or not group results agree
with majority predictions.

Wisconsin Standards:
Science Inquiry
C.4.2 ….ask questions…make observations, make predictions, and offer explanations.

C.4.6 Communicate the results of their investigations in ways their audiences will understand by using charts, graphs, ….

 

 Moon Phases and Eclipses: A Participatory Model

Materials and equipment: Styrofoam balls (about 10 cm. diameter) on sticks or pencils, bright (100W or 150 watt frosted bulb works well) light bulb (lamp without shade works well), table on which to set lamp, dark room (as large as possible)

Safety considerations: Be sure participants understand that sticks or pencils are for holding their “moon models” and not for assaulting others! The best approach is to glue pointed sticks or pencils in place so they cannot be pulled out and pose a hazard. Also, do not touch the light bulb. It will be very hot.

Suggested procedure:

The ball on the stick represents the Moon, the lamp the Sun, and the observer’s face the surface of Earth.

1. Form a circle around the light bulb. It should be the only light in the room. There should be enough room between participants so they can hold out their “moon model” at arm’s length and turn.
2. Have each person begin by holding the ball in front of his or her face. Then ask them to look across the circle. Do they see shadows? What are these called is this happens on Earth? (Answer: eclipse of the Sun) If each person moves the ball high or low enough, the shadow no longer falls on Earth because Sun, Moon and Earth are no longer lined up. This is usually the case in nature. Eclipses are relatively rare because perfect alignment occurs only occasionally.
3. Now have each person line up his or her ball with the lamp and look at it. Note that the side toward Earth (face) is dark because the Sun is lighting up the other side and that the Moon and Sun are close to being lined up. This is the phase called new moon when the Sun and Moon rise and set about the same time and the moon is not visible.
4. While still holding the ball out in front of his or her face, each observer should turn about 45 degrees (1/8 turn) to the left. Now note that the ball is illuminated with a crescent shape (waxing crescent phase) and that the Moon and Sun are no longer aligned. The Moon will have risen later and will set later than the Sun.
5. Turn farther, another 45 degrees, to see the Moon 50% illuminated (first quarter) and further still, another 45 degrees to see more than 50% but less than 100% (waxing gibbous).
6. Once observers have turned half-way around (180 degrees) while keeping the Moon high enough above their heads so as not to block the light falling on it, they can see the phase we call full moon. Now the Moon and Sun are in opposite positions in the sky. Moon rises at sunset and vice versa. If observers do line up the Sun and Moon with Earth (head) in between, the Moon will be dark. This represents a total eclipse of the Moon.
7. Continue to turn around to observe the rest of the phases: waning gibbous, third quarter, and waning crescent and back to new moon again.
8. To increase understanding of the phases, encourage observation at home (with families), and increase interest in the sky, have children keep a moon-phase diary with drawings of the moon each time they see it as well as a record of the time and its location in the sky.

Wisconsin Science Standards:
Earth and Space Science
E.4.4. Identify celestial objects (stars, Sun, Moon, planets) in the sky, noting changes in patterns of those objects over time.

E.4.6. Using the science themes, find patterns in the Earth’s daily, yearly, and long-term changes.

Physical Science
D.4.7. Observe and describe physical events involving objects and develop record-keeping systems to follow these events by measuring and describing changes in their properties, including position relative to another object, motion over time…

Science Connections
A.4.2. When faced with a science-related problem, decide what evidence, models, or explanations … can be used to better understand what is happening now.

Sorting and Classification

Suggested by an activity in the journal of the National Council of the Teachers of Mathematics

Learning Objectives:
Skills: classification based on analysis of information

Materials and Supplies:
Index cards or slips of paper: several for each person

Suggested procedure:
Each person in a group of 4-6 writes down the title, author, subject, audience, whether fiction or nonfiction, and any other information about 3 or 4 favorite books (variations: books most recently read, books being read for assignments, etc.). Each person shares the information with the rest of the group. Group decides 3 or more different criteria for classifying the books. Each criterion provides two groups (e.g. fiction or nonfiction). Then the group does the sorting by the first criterion, records the results, sorts by the second criterion, records, and then by the third. For one initial criterion, do the initial sort again and then choose a second criterion to sort one of the groups (e.g. first: fiction vs. nonfiction; second: books for children vs. books for adults). Continue sorting/classifying this way until you have run out of distinguishing characteristics or have only one item in each class. Report your classifying scheme to the class.

Extensions:
Classify other things: pictures of things, objects brought from home or found around the classroom, living things seen around school or home, etc.

Wisconsin Standards:
D.4.2, Group and/or classify objects…based on…properties

How Much Fat?

Learning Objectives:
Content: fat content in food, food testing
Skills: using instruments (mass balance), making observations, handling samples to prepare for testing

Materials and equipment:
Balances to measure weights of materials, scissors, brown-paper grocery bags, markers, plastic bags or plastic wrap, spoons

Safety:
Do not eat any of the food materials supplied. These foods are for testing purposes only. Be sure no one is allergic to any of the foods before anyone opens a jar, storage bag, etc. Clean up spills immediately.

Suggested procedure:
1. Cut open a brown-paper grocery bag to make a large rectangle. This will be the surface on which samples are applied. Draw circles about 10 cm in diameter on the rectangle with permanent marker. Label one circle FAT.
2. Weigh out equal amounts of shortening or vegetable oil (the control, because it is all fat) and other foods. Foods can be placed in sealed bags for weighing or handling. Alternative procedure: use the same volume of food by measuring out a teaspoon, tablespoon, several milliliters, etc.
3. Crush solid foods (like chips, cereal) inside bags or wrap and warm in hands to soften.
4. Smear the sample of oil or shortening into the FAT circle.
5. Smear each sample into a circle on the brown paper and label it.
6. Place the brown paper on a flat surface to dry. Inspect it when it is dry for fat residue. Compare to the FAT circle to get a sense of how much fat each food contains.
7. Clean up work area, discard all food residue, and wash hands.

Extensions:
Correlate observations of fat content with reading of food labels for prepared foods. Compare “reduced fat” and “fat-free” versions of foods with the “full-fat” versions.

Wisconsin Standards:
Science:
Life and Environmental Science: F.4.1 Discover how each organism meets its basic need for … nutrients…
Inquiry: C.4.4 Use simple science equipment…
C.4.5 Use data they have collected to develop explanations

Health:
A.4.3 Identify ways to be healthy
B.4.1 Identify responsible health behaviors

 Activity: Reaction Time

(An activity to use to connect to physical science, life science (human body) and health)

Learning objectives:
Content: human reaction time and what might affect it, falling bodies, gravitational force
Skills: measurement, averaging, calculator use

Materials and equipment: meter stick, pencil, paper, calculator for each group of three or more students working together

Safety considerations: Meter sticks are scientific instruments, not swords, clubs, etc.

Suggested procedure:
1. The tester (person #1) holds the 0.0 end of the meter stick between the thumb and forefinger (held about 4 cm apart) of the “test subject” (person #2) and drops it without giving a prior cue. The “test subject” catches it. The group’s recorder (person #3) writes down the distance the stick fell (the position of #2’s finger on the centimeter scale). Repeat the process 5 times for each test subject. Each person in the group should be tested catching with his or her writing hand.
2. Average the distance for each person and convert it to a distance (D) in meters.
3. Assuming the stick was falling freely under the influence of gravity alone, the distance D it fell is related to the time T (reaction time) by the following relationship:

T = ( 2 D/(9.81))1/2 seconds. (1)

Use equation 1 to compute the reaction time for each person using a calculator or set up a spreadsheet to do the computation for each person.
4. Compare results and discuss what affects reaction time. In particular, discuss health habits that would increase reaction time. How might changes in reaction time impact safety, ability to do tasks, etc.?

Extensions: Compare reaction times under different conditions:
Using other hand (left hand for a right-handed person and vice-versa), using audible rather than visible cues (test subject blindfolded, tester speaks when he or she drops the stick), before and after exercise, in a distracting environment (loud noises, etc.), etc.

Standards:
Science:
Physical Science: D.4.6. Observe and describe physical events in objects at rest or in motion
Life and Environmental Science: F.4.2. Investigate how organisms…respond to internal cues and external cues.

Health:
A.4.1 Identify…factors that influence health.
A.4.5 …… functions of human body systems.

 

 Dancing Raisins, etc.**

Learning Objectives:
Content: When an object’s average density is less than that of the fluid in which it is free to move, it floats. If greater, it sinks. An object’s average density will decrease if gas bubbles attach and increase if the bubbles detach or break.
Skills: observation, making hypotheses, planning investigations

Materials: clear carbonated beverages (7-Up, sparkling water, etc.), raisins, other dried fruits (dried cranberries, currants, etc.), small pieces of pasta (small shells, elbow macaroni)

Equipment: clear containers (2-liter soft-drink bottle with narrow top removed, clear pitcher, etc.)

Safety Considerations: Since this is an experiment, no eating or drinking the materials. Splash goggles should be worn when pouring the liquid. Glass containers should be avoided.

Fill a clear container almost full of with a clear carbonated beverage. Add a handful of raisins and watch what happens. Why does it happen? Discuss.

Extend this into an investigation by trying different liquids with the same “dancers” (raisins) or a variety of different “dancers” in a chosen liquid. What differences are observed? Why?

Wisconsin Science Standards:
Science Inquiry
C.4.2. …Ask questions, plan investigations, make observations, make predictions, and offer explanations.
C.4.8. Ask additional questions that might help focus or further an investigation.
Physical Science
D.4.6. Observe and describe physical events in objects at rest and in motion.

**I saw this activity done first by Don Tincher (Berlin Middle School).

 Paper Spinners: Starting Point for Investigation
Source:  Anne Goldsworthy at a workshop in Wales in 1996

Learning Objectives:
Content: falling bodies with acceleration due to gravity and air resistance
Skills: all aspects of INVESTIGATION planning, asking questions, formulating hypotheses and explanations, making appropriate graphs, displaying and discussing results
Materials: basic spinners, paper clips
Safety considerations: No one should be allowed to stand on a chair, table, ladder, etc. because of danger of falling. Spinners should be dropped from safe heights under supervision.
Spinner design:
Spinner is a rectangle 6 cm. X 10 cm with two lines(wing lines) 8 cm long beginning at the short edge at 2 cm and 4 cm from and parallel to the long edge:
<—–10 cm long—————————>
___________________________________

|______________________6 cm

|______________________ wide

|__________________________________|
|<——-8 cm—————>

Six spinners of this design can be drawn on an 8.5″ X 11″ sheet of paper and copied in a standard photocopy machine on paper, light card stock, etc.
Cut out a spinner, cutting also along the 8cm-long “wing” lines. Fold one outer (wing) strip forward and the other backward so that the wings are perpendicular to the rest of the spinner. Add a paper clip to the bottom of the middle strip. Drop from shoulder or head height and observe the motion.
Investigate this system by changing some aspect (the independent variable) such as number of paper clips, color of paper, direction of the folding of the wings, stiffness of paper and observe the effect (the dependent variable) such as time of fall, rate of spinning, etc. Graphically represent and discuss the results. Discuss why each effect might occur.
Extensions:
Come up with as many ways as possible to vary the system and investigate the effect of each on the time of fall. When varying size, consider surface AREA as well as linear dimensions and plot data accordingly.
Choose alternative dependent variables (e.g. number of spins), methods of timing, etc.
Wisconsin Standards:
Physical Science
D.4.7. Observe and describe physical events involving objects and develop record-keeping systems to follow these events…including…motion over time and position due to forces.
Science Inquiry
C.4.2 ….plan investigations, make observations, make predictions, and offer explanations.
C.4.6 Communicate the results….in ways the audience will understand by using charts, graphs, drawings, etc.

 

 Screecher (a.k.a. clucker, noise generator, etc.)**


Learning Objectives
:

Content: sound (pitch and loudness), friction, noise
Skills: hammer use and safety, posing questions and doing investigations, manipulation of materials

Materials and equipment: steel cans (various sizes), hammer, large nail, string, paper clip, scissors; scraps of fabric, sponge or paper towels

Safety considerations: When working with hammer, observe a “circle of safety” so no one will be struck accidentally. Do not hold a nail for anyone else. Watch out for rough edges on cans and cover any with tape to avoid cuts.

Procedure:
Punch a hole in the center of the can. Cut a piece of string more than a half meter long. Put one end of the string through the hole from outside to inside and tie a paper clip onto the end inside the can. Wet a piece of fabric, sponge or paper towel and use it to pull on the string. Does the sound depend on the size or shape of the can? What characteristic of the sound changes? (Consider pitch and loudness.) Try a variety of cans.

Extensions: Investigate a variety of types and sizes of strings and cans or position of the hole in the can to determine if these changes affect pitch and/or loudness.

Wisconsin Science Standards:
Science Inquiry
C.4.2 Investigation…
Physical Science
D.4.8. Sound
D.4.2. Classification of objects by properties

** My first opportunity to make a screecher was at WESTfest. I have seen several versions of it since.

 Constructing an Equal-Arm Balance

Materials and equipment: wire coat hangers, plastic cups (the narrower and deeper the better), sturdy tape (clear package sealing tape-not the hand tear type, duct tape, etc.), masking tape, light string, washers, permanent markers, pliers.

Learning Objectives:
Content: Mass (inertia, the amount of matter in a body that resists acceleration when force is applied) can be measured by comparing a quantity of standard masses to the unknown mass with an equal arm balance. The gravitational force on each side will the same when the masses (and therefore also the weights) on each side are the same when the balance is balanced.
Skills: construction skills including taping, using simple tools, determining balance point, measuring, tying knots, using the completed balance to make a mass measurement

Safety considerations: be careful when using tape dispensers and pliers that fingers are not cut or pinched

Procedure: Bend the semicircular loop (Ç) at the top of the hanger so that it makes a point (Ù). This assures that the balance will swing from a single point rather than shift from one side of the semicircle to the other. Then tape a plastic cup at each end of the bottom of the hanger.

Cut a length of string about 3 times as long as the distance from the “neck” of the hanger to the horizontal bottom wire. Tie one end around the neck and tie a washer to the other end.

Calibrating the “balance point”: Place a piece of masking tape around the middle of the horizontal bottom wire. Hang the apparatus from a hook or nail. With nothing in either cup, mark on the masking tape where the string rests when it has finished swinging back and forth. When the cups are loaded-one with “know weights” and the other with the quantity to be weighed-the system will be balanced (the known and unknown weights equal) when the string returns to this point.

Wisconsin Science Standards:
Science Inquiry:
C.4.4. Use simple science equipment… effectively.

Physical Science
D.4.1. …measuring properties of earth materials, including properties of …weight…

The Color of Energy

Learning Objectives: Scientific background in light, color, phosphorescence:
The energy E of a photon (particle of light) is given by

E = h c/L (1)

where h is Planck’s constant (6.63 X 10-34 Joule-seconds), c is the speed of light (300,000,000 meters per second) and L is the wavelength (distance between maximum occurrences of electric force along the photon/wave path). When we observe different colors of light, we are sensing different light energies or combinations of them. Red has the largest wavelength of visible light (about 0.000000650 m) and, therefore, the lowest energy. Violet has the shortest wavelength and highest energy of visible light (about one and a half times as much as red). Ultraviolet light has more energy per photon than any form of visible light and infrared light less than any visible form.

In glow-in-the-dark (phosphorescent) objects, the object absorbs energy from the light falling on it. Some of that energy is reradiated slowly. In the light, an object reaches equilibrium emitting and absorbing at a constant rate (often too dimly to be seen in the light) in a few minutes, but in the dark it can only emit light in some color (corresponding to a particular energy) until all the absorbed energy is gone. The color depends on the details of the phosphorescence process and usually only occurs at one energy (color) in a given material. If a phosphorescent material radiates in yellow light, it must be exposed to photons with at least as much energy as yellow photons have. Red photons could not excite the yellow phosphorescent process because they do not have enough energy individually (and two or more photons can’t get together to combine their energy). White light (all colors) or light containing violet, blue, green, and yellow as well as orange and red should be able to excite a material that glows in yellow, but light with just orange and red would not. If a phosphorescent material glows in orange, however, orange light (and white light and violet, blue, green, and/or yellow light) would excite it.

Learning objectives: skills: observation, handling materials (including under conditions of darkness), mixing, measuring; charting results

The activity:
(This activity is probably best done after an exploration and investigations with rainbow glasses or peepholes to see what colors are transmitted by colored water, plastic sheets, etc.)

Materials: glow-in-the-dark stars that glow in yellow/green but that have been kept in the dark for a long time, clear plastic cups, rulers, markers, water, food coloring (red and blue at least), stirrers to mix coloring and water, bright source of white light with all colors present.

Facilities: room that can be completely darkened

Safety considerations: Nothing used for the experiment is to be tasted. When working in the dark, children must remain seated and follow directions so spills, etc. can be minimized. To safeguard clothing from spills, children can wear “lab coats”.

1. Each group begins with 4 cups and 4 each of yellow-glow and orange-glow stars that have been kept in the dark at least since the previous day.
2. With room lights on in room that can be made completely dark and stars remaining in the dark (closed opaque boxes or envelopes) mark a line 2.5 cm from the bottom of each cup with marker.
3. Fill three cups to the line with water. Leave one empty.
4. Add 10 drops of red food coloring to one cup with water in it, 7 drops of blue to another.
5. Position cups and containers of stars so they can be manipulated in the dark. Make sure everyone is seated with equipment and materials within reach.
6. Lights off. Room completely dark. Place one yellow-glow under each cup (they should be small enough to fit). (The empty cup and cup with clear water are the controls.) Verify that all stars are in place.
7. Turn on lights and leave on for 15 minutes or so, making sure cups are not disturbed.
8. Have everyone take their places in preparation to turn off the lights again.
9. When all are settled, turn off lights. Before moving cups, observe any visible glow. Then move cups from stars. Do stars glow that were under no water, blue water, red water, clear water?
10. Discuss findings and reasons.

(Expected findings if all goes well (and why): Under clear water and no water, stars glow brightly because they were exposed to full range of colors, including light with energies large enough to excite yellow and orange phosphorescence. Those under the blue water (filters out red but not blue light) should glow reasonably well, although perhaps not as brightly as the “controls”. They received less light but light with enough energy to excite them. Under the red water, the yellow-glow star glows not at all or very faintly because the light reaching it did not have enough energy.)

Further investigations:
1. Vary the amount of red food color and observe the effect of exposure. How much is needed to filter out the violet/blue/green/yellow but still allow some light to pass?
2. Vary the amount of blue food color and observe the effect of exposure. How much is needed to allow some light to pass and cause excitation?
3. Try different glow-in-the-dark materials. In what color(s) do they glow, how long to they glow visibly, etc.?
4. Try various filter materials (translucent plastic sheets, markers on clear plastic, Jell-O, etc.) What colors/energies of light pass through them? Etc,

Wisconsin Science Standards:
C.4.4 (collect data); C.4.6. (..chart); C.4.8 ask additional questions
D.r.8 …substances that cannot be touched (..energy, light..)

Bouncing Ball: Energy, Elasticity, Mathematical Analysis

Learning Objectives:
Content: Potential energy, kinetic energy, energy conversion, elasticity, energy conversion to heat and sound with “nonconservative” forces such as friction and air resistance
Skills: measurement, averaging, graphing, computer analysis

In real-world interactions, energy is often converted from “more useful forms” such as kinetic energy or gravitational potential energy to “less useful” or “dissipated” forms such as heat or sound. While not truly “lost”, the “dissipated” energy is not readily recoverable and put to work. A system as simple as a bouncing ball allows the observation of energy “dissipation”. If a ball is dropped from a height H and bounced back to height H’ (less than H) it has dissipated ((H-H’)/H) X 100% of its original energy into such less useful forms as heat, sound, etc.

Materials and equipment: ball, meter stick, graph paper, computer

Safety considerations: Ball is not to be thrown at any person, at the floor, or at any object in the room.

Suggested procedure: Drop the ball onto a hard surface from 5 or more different heights and measure the height to which the ball bounces back. Do each height several times and average the result.

Analysis: (In each case the number(s) obtained is (are) the coefficient of restitution K of the ball. The smaller the value of K, the more energy is dissipated.)
1. Numerical: Take the ratio of bounce height to drop height for each drop height used. Average the results. Is there a trend? Does the coefficient change systematically as the drop height increases?

2. Graphical: Graph bounce height (vertical axis) versus drop height (horizontal axis). Draw a “best fit” straight line through the data points and compute the slope of the line. The slope is the coefficient.

(Note: To compute slope, divide the amount of change of bounce height by the corresponding change of drop height. See example)

3. Computer: Using Excel, make a table of drop heights (first column) and corresponding bounce heights (second column). Using Chart Wizard create an x-y scatter graph. Once the graph has been created, click inside the graph area, then click on chart and pull up “Add trendline” and choose “linear”, then click on options and check off “show equation” and “show R-squared” before clicking on OK. The equation gives the computer fit with the coefficient of x as the coefficient of restitution, K.
Follow-up investigations:
1. Try different balls on the same surface. How do their K values differ? Can you predict higher K without bouncing?

2. Try the same ball on different surfaces. Why are bounce heights different?

3. Consider other variables (e.g. temperature)

Wisconsin Science Standards:
C.4.4 Uses simple science equipment…to collect data..
C.4.6….Using charts, graphs,…

D.4.6. Observe and describe physical events in objects at rest or in motion.
D.4.7. ..including position.., motion over time, and position due to forces.
D.4.8. ..substances that cannot be touched (forms of nergy…sound..)

Activities  with “Rainbow Glasses or “Rainbow Peepholes”
Spectral Identification and Blackbody Radiation

rainbowpeep

Background information
Types of Spectra:
Spectra are generally classified into 3 types:
a. Line spectra from luminous low pressure gases (Atoms are far apart, so emitted energy shows transitions between discrete energy levels in atoms.)
b. Continuous spectra from luminous high pressure gases, liquids, and solids (Atoms are close together and share energy. Spectra are often functions only of the temperature of the luminous material because they are behaving like blackbodies. In such blackbodies, the hotter the object, the shorter the wavelength of light at peak intensity. For stars, where this peak may be in or near the visible range, the bluer the star’s appearance, the hotter the star.)
c. Absorption spectra from dense, luminous objects surrounded by cool/non luminous atmospheres or other filtering material (The filter absorbs selected colors, leaving a continuous spectrum with dark lines or gaps.)
How “rainbow glasses” work:
(Note:  An excellent source of rainbow glasses and peepholes is Rainbow Symphony in Reseda, CA)
The “lenses” in the “rainbow glasses” (or the opening in the “rinbow peephole”)are actually diffraction gratings created with many, many parallel vertical and horizontal lines. When light strikes these it spreads out and its direction changes. Interference occurs as the light scattered by the lines comes together at various directions in space. Because constructive interference depends on the wavelength (color) of the light, bright images of the constructive interference of red light will appear at different angles than those of blue, etc. and the spectrum (rainbow) from a light source is spread out.

Safety Warning: Never look at the Sun with rainbow glasses, peepholes (or anything else). Do not look directly at lasers (even laser pointers) either.
To safely view sunlight, observe the moon!

Activities:
Observe spectra of various luminous objects including
Incandescent light bulbs (clear, white, and colored);
Candle, gas flame, campfire; fluorescent light;
Glowing element of electric range or hot plate;
Gas discharge tube (obtain from physics teacher?);
Glow-in-the-dark objects of different colors;
“neon” light (such as restaurant sign); streetlights;
Light bulb with colored filter in front of it;
Hotter versus cooler light bulb; firefly;
Moon, bright planet, and any other luminous object you can find.

Wisconsin Science Standards:
D.4.8 … make observations of …substances that cannot be touched (…light…)

 Drops on a Penny
(adapted from a lesson by Sandy Juedes, Ripon Middle School)

Learning Objectives:
Content: surface tension, properties of water and other liquids
Skills: manipulating simple equipment (dropper), predicting, counting, posing new questions and planning new investigations
Materials and equipment:
Paper towels, plastic droppers, pen or pencil, plastic cups to hold water (one for every 2 or 3 people)
Safety considerations: droppers are scientific instruments, not squirt guns!
Procedure:
1. Place penny on paper towel. Draw some water into dropper and then practice squeezing out uniform drops (to fall back into the water cup). Dropper should be held upright. Note how large drops are.
2. Predict how many drops can be placed on a penny before the water spills over and write down the prediction.
3. Proceed to drop water onto the penny. Do not touch dropper to water on penny. Drop water from 1 cm or so from the penny. Count the drops. Note shape of the collection of water on the penny.
4. Write down the number of drops the penny actually holds. Discuss how it agreed with your own and other predictions. Talk about why the number might be larger (or smaller) than predicted.
5. Have someone draw a picture of what the “bubble” of water looks like before it breaks. What might cause this effect.
Extensions: What could be changed to alter the number of drops a coin will hold? Do an investigation of these variables.
Wisconsin Science Standards:
Science as Inquiry:
C.4.4 Use simple science equipment… to collect data relevant to questions and investigations.
C.4.8 Ask additional questions
Physical Science:
D.4.2 …properties of earth material

 Giant Bubbles in the Making
from Mary Williams-Norton, Ripon College

Materials: Knitting worsted weight acrylic yarn, about 20 grams, wound into a ball with yarn double, one plastic ring (2.54 cm or larger diameter)
Bubble solution: 0.5 cup good quality dish-washing liquid, 2-3 Tablespoons glycerine or Karo syrup (optional) mixed gently into enough water to make one gallon of solution. For good results, mix a large quantity of solution a day ahead and let stand in cool, dry place.
Equipment: crochet hook size K (optional)

1. Using double strand of yarn throughout, chain 230 (or keep making chain stitches until yarn runs out). The chain may be made using a crochet hook or by “finger crochet”.

2. Using an overhand knot, tie a 3 cm wide loop 1/3 of the way along the chain.

3. Slip the ring onto the longer part of the chain, then tie the ends of the chain together securely with double square knots. Cut off yarn ends, leaving about 1 cm of each end at the knots. (When the bubble maker is submerged in soap solution, the yarn will stretch. If the ends are cut off too short, the knots may come apart.)

4. Tie a loop about 3 cm wide at the position of the knotted ends also.

5. To make bubbles, submerge bubble maker in bubble solution, holding loops together. Once the bubble maker is well saturated, draw it out slowly, keeping loops together. Draw loops apart to create bubble film. Swing bubble maker gently or allow wind to push the film into a bubble. To close bubble and release, bring loops back together. Cool, humid, cloudy days with light winds seem to provide the best outdoor conditions for creating nice bubbles, but you can create spectacular bubble films anywhere.

Safety considerations: Avoid working on sidewalks, playgrounds, etc. because the bubble solution is so slippery that pedestrians may slip and fall. Avoid getting solution in eyes.

Extensions and Investigations:
Experiment with different bubble mixture to make the “strongest” and largest bubbles. Make bubbles using different objects or “by hand”.

Observe bubble colors outdoors and indoors in white light. Make half-sphere bubbles on table tops and looks at them under monochromatic light (light bulb with red, blue, gree, etc. filter). Note the differences in the color bands (from light interference).

Wisconsin Standards:
Science Inquiry
C.4.2…plan investigations
Physical Science
D.4.8…observe light

 The Wave Bottle

Learning Objectives:
Content: Less dense fluids float on top of more dense fluids regardless of the order in which they are poured into a container. Certain fluids do not dissolve one into the other. When mixed together, they will eventually separate again with the less dense fluid floating on top of the more dense one. At the fluid interface waves can move and be seen if fluids are contrasting in color.
Skills: following directions, measuring and estimating, manipulating fluids.
Materials: clear plastic bottles with tightly fitting caps, vegetable oil (mineral oil works better but is more expensive), water, food coloring
Safety Considerations: When using hot water to remove labels, be sure water is not hot enough to scald. Wipe up liquid spills, especially of oil, to avoid slipping and falling.
Suggested procedure:
1. Remove label: Fill bottle with label on it with hot tap water. Wait a short time until glue softens and label can be peeled off. Dump out hot water.
2. Fill bottle halfway with oil. Add cold water already colored with food coloring until bottle is full. Cap tightly!

3. Shake bottle vigorously and then watch the appearance change. Once oil and water have separated, move bottle to create waves.
Wisconsin Standards:
Physical Science:
D.4.1: Understand that materials can be made of more than one substance…observing…the properties of earth materials…
Science Connections:
A.4.2: Decide what… models…

 Rainbow in a Bottle

With just the bottom of a clear 2-liter bottle as a containter, it is possible to show that water is capable of separating white light (from a flashlight, for example) into its full spectrum (red, orange, yellow, green, blue, indigo, violet or ROYGBIV, for short).

Adding a mirror makes it possible to make a bright rainbow in reflection-almost** like the real thing-by placing a small mirror at an angle into the container and setting it in a sunny window so that sunlight strikes the mirror. A rainbow (**shape is different) appears above the mirror and can be projected on a piece of white paper or a white wall. (This can also be done with a flashlight, although the effect is much less dramatic.)

Materials: Bottom of clear 2-liter bottle (cut off about 20 cm. from the bottom), small mirror (edges taped or enclosed), water, white paper or poster board; bright flashlight; small containers (foam, paper, etc.) to hold water, plastic droppers, waxed paper.

Safety: handle glass mirrors carefully: do not use any with cracks or sharp edges

Procedure:
1. (To show that water can separate white light into colors) Fill bottom of 2-liter bottle almost full of water. One person should shine the flashlight at edge and adjust angle while another person hold a piece of white paper to act as a screen to observe the “rainbow”. Keep adjusting to see the widest strip with all the colors.

2. Place a mirror in the container of water. Adjust mirror angle and container position in sunny window until sunlight is on the mirror and rainbow is projected upward. (Although it does not work as well, the effect can also be seen with a bright flashlight. If you need to use the flashlight method, do it in the darkest place available or it may be impossible to see the colors.) Observe colors-order and intensity-as well as shape of “rainbow”. In what ways does this differ from a rainbow as seen in the sky?
Note that this rainbow is in front of the reflector (mirror) and is being projected back towards the Sun. (In a sky rainbow you must stand with your back to the Sun to see the rainbow also.) Perhaps in a sky rainbow, something is reflecting the light back to you as well as splitting it into colors. What could that something be?

2. Can water reflect light? To see that it can, put some water in a bowl and look at it. Can you see your reflection? Can just a tiny drop of water reflect? (Drop water on waxed paper and look for reflections of overhead lights, etc.)

Wisconsin Standards:
Physical Science: D.4.8 Observe light

Balloon Jet Rotor
adapted from an activity introduced by Don Tincher,
Berlin Middle School

Materials: pencils with eraser ends, long (3 or more cm)pins with large heads, flexible-type plastic straws, 7 inch balloons, tape (“magic tape” or electrical tape: masking tape doesn’t seal and duct tape is too heavy)

Safety: Balloons are a choking hazard, particularly for younger children. “Prestretch” and leak-test balloons by blowing up each one with a balloon pump (more hygienic than by mouth!) before the activity. Also make sure that the children handle the pins carefully. This activity is unsuitable for children unless they have enough dexterity to handle the pins and manipulate the tape easily.

Procedure: Tape a balloon to the end of the straw farther from the flexible section. Use enough tape to make an “air-tight” seal of balloon to straw. Push pin through straw close to tape and “work” the pin around so that the hole is larger enough so that straw does not bind but not so large that a huge amount of air will escape. Push the pin into the eraser at the end of a pencil, bend the flexible section so that the short end of the straw is perpendicular to the long section, blow up the balloon through the straw, let go, and observe.

Please note: This IS rocket science!!
This system uses rapidly escaping air from the straw (jet propulsion principle) to create a thrust (force). Because this force is perpendicular to the “lever arm” connected to the rotation point, the force creates a torque which causes the system to rotate. As long as air is escaping, the torque is acting and-if friction at the axis is small enough-the rotor will spin faster and faster (accelerate). When the air runs out, the spinning slows down because friction at the axis provides a torque in the opposite direction that eventually stops the motion. Try changing the angle of bend from perpendicular to parallel and note that the amount of rotation decreases. (Torque is maximum when force and lever arm are perpendicular.) You can also investigate the effect of shortening the lever arm by shortening the long section of the straw.

Wisconsin Science Standards:
Science Inquiry:
C.4.2 …Ask questions, plan investigations, make observations.
C.4.4 Use simple science equipment.
C.4.8 Ask additional questions…
Physical Science:
D.4.6 Observe and describe physical events in objects at rest or in motion.
D.4.7 ….Follow…events including motion over time and position dues to forces.

 Milk Kaleidoscope
Also suggested by Don Tincher

Learning Objectives:
Content: surface tension, milk as a complicated suspension, fluid density
Skills: observation, description, drawing, proposing investigations, explaining

Materials and Equipment: milk (several varieties, if possible), food coloring, liquid dish detergent, shallow pans (foil pie pans work well), droppers

Safety: Of course none of the ingredients should not be ingested before or after mixing

Procedure: Pour milk into pan to depth of about 2 cm. Place a few drops of each food color at four positions separated from each other around the pan. Observe what occurs for 2-3 minutes. Then drop in a few drops of dish detergent (near one of the color areas works well) and observe. What happens? Speculate as to why? What would happen in water? (Predict and then try it.) How are milk and water different? What is the difference between whole and skim milk? Does what you observe make sense in light of these differences?

Note: this activity should probably follow doing an activity such as “drops on a penny” with both plain water and detergent/water solution so that students are aware of the effects of detergent on surface tension.

Wisconsin Science Standards:

Science Inquiry:
C.4.2: Use the science content…to ask questions, plan investigations, make observations, make predictions, and offer explanations.

Physical Science:
D.4.2: Understand that objects are made of more than one substance…
D.4.4: Observe and describe changes in form…
D.4.5: Construct simple models of what is happening to materials and substances undergoing change…
D.4.7: Observe and describe physical events…describing changes in their properties…and position due to forces.

 Marshmallow Movers
An activity devised by Marilyn Fox (Grade 2 teacher, Markesan, retired)

Materials: marshmallows, graham crackers, pretzel sticks, bread sticks, etc.; waxed paper to cover all surfaces where food will be handled.

Safety: This experiment is designed to be eaten. Just this once it is acceptable to consume the materials as long as they have been handled under hygienic conditions. Experimenters must wash hands before beginning, not touch each other’s materials, and throw away any materials that fall on the ground.

Procedure: The objective of this activity is for the experimenters to play around with the materials and then construct an “original” method of moving a marshmallow. In the process of investigating they will discover many of the properties of some of the “simple machines” (lever, wheel and axle, inclined plane). As such, this activity is an excellent way to begin a unit on simple machine, work, energy, motion, etc. After each person has made a “marshmallow mover”, he or she should demonstrate it to the rest of the group and everyone should notice similar uses of various elements of simple machines appearing in the various designs.

This introductory activity could be expanded to include investigations of specific systems. It could also be used as science-discovery activity at a family science program or as part of a science-sharing session between older and younger children.

Wisconsin Science Standards:
Physical Science:
D.4.6: Observe and describe physical events in objects at rest or in motion.
D.4.7: Observe and describe physical events involving objects…including position relative to another object, motion over time, and position due to forces.

Science Inquiry:
C.4.4: Use simple science equipment…to collect data relevant to questions and investigations.

 Color Mixing
Another activity devised by Marilyn Fox, Markesan School District (retired)

Materials: clean white paper, waxed paper, white frosting, food coloring, plastic spoons

Safety consideration: If the process is handled hygienically (clean materials, clean hands, no sharing), the products can be eaten

Procedure:
Begin with a large blob of white frosting. Divide it into three parts and place at three points (imagine an equilateral triangle) on white paper. Mix red food coloring into ones, blue into the second, and yellow into the third to generate equally intense colored frosting. Then mix a little (equal amounts) of each adjacent color in space half way between them. Repeat with all three pairs (secondary colors). In between the secondary and primary, mix equal amounts of primary and seconday to form the other colors. Mix one secondary with another to form others. What would you name each color you make? (Be imaginative.) What happens if you mix equal amounts of all three primary colors together? Try making up a mixture to create your favorite color.

Wisconsin Science Standards:
Physical Science:
D.4.4: Observe and describe changes in…color…

Science Inquiry:
C.4.4: Use simple science equipment…

 Oobleck


See Dr. Seuss’s Bartholomew and the Oobleck for literary background
and Oobleck: What Do Scientists Do? from Lawrence Hall of Science
for classroom projects for students

Materials and equipment: water, cornstarch, food color (optional: green for “authentic” Oobleck), mixing containers, plastic spoons, zip-loc bags to store and transport Oobleck

Learning Objectives:
Content: differences between solids and liquids
Skills: measuring, mixing, defending an argument with evidence

Safety considerations: Although the materials are not toxic, they should not be consumed or tasted, especially after lots of people have handled them.

Procedure: Begin with a quantity of dry cornstarch in a large container. Add water slowly, mixing after each addition. When the material nears the “Oobleck” state, it will contain fluid and dry areas but feel hard to the touch. Add water only sparingly after this point. If you add too much water you will end up with only a cornstarch/water suspension.

Once in the “Oobleck” state, experiment with the material. Note that if you push hard, it feels solid but if you push on it gently, you can push your finger through it. You can pick up a handful or break a piece into two, but it you wait, it will flow through your fingers.

What is your definitions or solid and liquid? Based on these definitions, what is Oobleck?

Investigation possibilities: What is the best “recipe” for Oobleck (expressed in volume of cornstarch and volume of water or mass or cornstarch and mass of water) to yield Oobleck with the most interesting properties? How long does it take Oobleck to flow depending on slope, etc.? For a particular Oobleck recipe, how long does it take to flow through a hole depending on hole size? etc.

Wisconsin Science Standards:
Physical Science:
D.4.1: Understand that objects are made of more than one substance.
D.4.2: Group and/or classify objects and substances…
D.4.3: Understand that substances can exist in different states-soli, liquid, and gas.
D.4.7: Observe and describe physical events…including position due to forces.

Science Inquiry:
C.4.7: Support…conclusions with logical arguments.

 Static Electricity

Materials: balloons, water, oil, salt, paper scraps, string

Facilities: clean chalkboard

Activities tend to work much better in DRY weather.

Safety: Because these activities use balloons, there is the usual hazard if children blow up the balloons by mouth. Blow them up ahead of time and/or use a balloon pump.

1. Electric personality:
When a balloon is rubbed in someone’s hair or on woolen or cotton clothing, the balloon will pick up electrons and become negatively charged. When brought close to a neutral object, the negatively charged balloons will repel electrons closest to itself on the object, leaving an “induced” net positive charge there. If the attraction between the induced charge and negative charge is large enough, the balloon will stick. Eventually, however, positive ions in the air will drift toward the balloon, neutralize its charge, and it will fall. Whoever can put the most charge on the balloon should have that balloon stay up the longest on a chalkboard.

2. Polar or nonpolar:
Some molecules (e.g. water) are slightly electrically polar (more positive on one end and negative on the other although neutral over all while others (oil) are non-polar. A stream of droplets of polar liquid will be attracted toward a charged object (balloon) while a non-polar one will not. Trying holding a charged balloon near (not in) a stream of water: note the effect. Then pour oil near the balloon to see the difference.

3. Stronger than gravity:
The electrostatic force is indeed much stronger than the gravitational force but only acts on charged objects (or neutral objects in which charge is separated (as is #1 above). A balloon can pick up small bits of material. Try a number of substances to see which works best.

4. Like charges repel

Charge two balloons all around. Tie one to one end of a long thread and the other to the other end. Hold the thread in the middle–away from you so the balloons don’t stick to you–and note that they push each other away.

Wisconsin Standards:
D.4.8 (Light, Heat, Electricity, and Magnetism)
Substances that can’t be touched (…electricity)

C.4.2: Make observations,…offer explanations

 

Take a Hike! Scale Model of the Solar System

MWN_mewn_ysgol
It’s a nice day.  Let’s hike to Neptune!

This activity was suggested by and adapted from

THE THOUSAND-YARD MODEL,
or The Earth as a Peppercorn (Copyright 1989 by Guy Ottewell)
(see
http://www.noao.edu/education/peppercorn/pcmain.html )

The model: Note the solar system scale model in the table below. The diameters of the planets are given in kilometers (km) and the average distances of each planet from the Sun in millions of kilometers (mil.km). Then the system is scaled down so that Mercury, the smallest planet, is less than 1 millimeter (mm) in diameter and all the other bodies’ sizes and distances are expressed on the same scale. the Sun is represented by a yellow beach ball (with smiley face) about 9 inces (230 mm) in diameter. (These balls are readilyt available from Oriental Trading Company ) If a different size Sun is used, of course, the planet sizes must be scaled up or down accordingly using a spreadsheet such as Excel to do the calculations.

Materials: 9 inch diameter beach balll, driveway markers, Play-Doh or plastic clay, index cards, tape. rulers with millimeter scale

Safety considerations: When doing the hike along a roadway, be sure all members of the group walk safely and that the group stays together. Have enough supervision (1 adult per every 7 to 10 children, depending on the age of the children).

Suggested Procedure
a. To get a sense of the relative sizes of the planets, mold the planets out of plastic clay or Play-Doh to make spheres of the correct size.

b. Choose a pleasant day and gather a group to “hike out” the distances from planet to planet. Begin at the corner of a long street and mark the location of the Sun (driveway markers with reflectors work well to mark locations along the curb). Pace out the distances to Mercury, Venus, Earth, Mars, etc., placing a marker at each location. Look back toward the Sun occasionally to appreciate the distances involved. Note that the pace (step) length assumed is about 0.6 m (60 cm). Keep going planet to planet until you run out of road, time, or energy. How far did you get? What does this exercise teach you about the size and density of the solar system? Note your observations.
Wisconsin State Standards:
Earth and Space Science:
E.4.4: Identify celestial objects…

Solar System Scale Model:
1 mm= 6089 km; Pace length = 0.6 m (60 cm)
(Sun is an 22.8 cm diameter yellow beach ball.)

BODY        BODY’S     BODY’S         BODY’S       BODY’S AVG.*              SEPAR. from last orbit
                  RADIUS      DIAM             DIAM           DISTANCE                   (paces)
                  (mil. km.)   (mil. km)       (mm: scale)     (mil. km)
Sun            696000     1392000          228.6                     0 0                              0
Mercury       2440           4880                0.8 5                 57.9                            16
Venus           6050          12100               2.0                  108.2                           14
Earth             6378         12756              2.09                 149.6                           11
Earth (July, farthest from Sun)                                   152.1                            11.4
Earth (January, closest to Sun)                                  147.1                           10.6
(Moon           1738            3476              0.57 located 6.3 cm from Earth)

Mars              3394           6788               1.11                 228                              21
Asteroid Belt
(e.g.Ceres)                       940                 0.15                420                               53  DP
Jupiter            68700     137400              22.6                 778.3                            98
Saturn            57550     115100              18.9                1427                             178
Uranus           23550       46710                7.7                 2871                            395
Neptune         24700      49400                 8.1                 4497                            445
Pluto*              1700        3400                 0.57                5913                            388 DP

* Average distance information is given for each planet except for Earth, where average, aphelion and perihelion distances are all specified. Due to its rather eccentric orbit, Pluto was actually closer to the Sun than Neptune until early in 1999.

DP denotes Dwarf Planet

(Note:  on this scale,1 light year of distance would be equivalent to about 1550 km (almost 1000 miles)!  That means that one would have to walk a distance of about  6700 km (about 4200 miles) to reach  Proxima Centauri,the star nearest the Sun. )

Designer Constellations

This is a good and simple activity to use with any group before introducing the concept of a constellation or talking about constellations in conjunction with mythology or legend. This activity should reinforce the concept that constellations are human inventions to impose useful and memorable patterns on randomly distributed objects.
Safety: Handle “edibles” hygienically.
Materials:
Black or blue paper, stick-on foil stars or small colored or metallic dots (the peel-and-stick variety work better than those that have to be moistened), pencil (or white chalk if using black paper); small foam packing bits OR air popped popcorn OR caramel corn OR M & M’s.

Drop at random (with eyes closed, perhaps) a dozen or so bits (foam, popcorn, etc.) onto the paper. Look for a recognizable pattern. If you see one, replace each bit with a foil star or colored dot. If not, toss the bits onto the paper again and look again. (You may eat the popcorn or caramel corn now or throw it away.) With pencil (or chalk, if using black paper) draw in details of your picture, name it, and add your name. Discuss what patterns activity participants saw and how they named them.

Alternatives and Extensions:
1. Give everyone the same pattern of dots and have each one find his or her own pattern. You might use an actual pattern of stars from some region of the sky and follow it with a study of the variety of stories told by different groups about the same constellation.

2. Give each person the pattern of dots for a constellation with which they are not familiar. Compare the patterns they devise with each other and the standard constellation.

3. Generate a pattern of dots by placing a piece of tracing paper over a state or county map and tracing the cities, towns, and villages around your own. Design a constellation from this pattern, name it, and then name the cities, towns, and villages by their location in the constellation. (e.g. Imagine that your constellation is a turtle. One village on its foot might be “hind foot of turtle”, another “turtle’s eye”, etc.) Draw analogies with naming or prominent stars, e.g. Betelgeuse meaning “armpit of giant”.

Wisconsin Science Standards:
Earth and Space Science:
E.4.4: Identify…patterns.

 Making Craters
(Reference: Moons of Jupiter, Lawrence Hall of Science)

Materials and equipment: flour, cocoa powder, marbles or small rocks, large plastic dish pans, storage tubs or containers to hold flour, rulers and/or meter sticks.

Safety considerations:
When attempting to drop objects from greater heights, use only safe methods (step-ladder rather than chair on top of table, etc.) of climbing. Do not throw the rock or marble unless everyone is standing behind the thrower.

Procedure:
To simulate the cratering of the Moon, Earth, and other planets in a semiquantitative way, a “planetary” surface of flour covered with a thin layer of cocoa poweder (for constrast) in a dishpan or large tub works well. Cover the surrounding floor with newspaper–ejected material goes a long way-or work outside on grass. Drop small rocks or marbles from a variety of heights, observing each time what occurs. The flour layer should be deep enough so the projectile stops in the flour before reaching the bottom of the container. (Begin close to the surface and go upwards to the maximum safe height by standing on a table or stepladder, if available.) To “resurface”, gently shake the container and/or smooth the surface. Try not to pack it down however, especially if you are making comparative measurements of crater diameter or depth. Note not only the depth of the craters but also the diameter and distance ejected material travels. Look for rays, lines of ejected material travel that go out in all directions from the crater. Observe craters on the Moon (on slides or through a telescope) and search for similar features. Note how an object hitting the surface at high speed (dropped from great height so that it has lots of potential energy to tranform to kinetic energy of impact) makes a much larger hole than its own size.

Investigations:
How does the size, shape, or density of the projectile affect crater size? What happens if the projectile comes in at an angle? What happens when projectiles hit water rather than “land” as meteoroids would more likely do on Earth?

Wisconsin Science Standards:
Earth and Space Science:
E.8.5: Analyze the geologic…history of the earth, including change over time…

Science Inquiry:
C.4.8: Ask additional questions that might help…an investigation.


Soup Can Race

Note: Because of the complexity of concepts, this would be an appropriate assessment activity after a study of energy (kinetic, potential, rotational, heat generated by friction, etc.)

Safety: Have a “spotter” for each can so that the cans aren’t dented and so they won’t go flying all over the room. Have the sloped table set apart from the rest of the room so there is space to watch that is away from the table itself.

Materials and facilities: Long, smooth, flat table; blocks to raise legs at one end a few inches; soup cans all the same size and mass (if possible): broth, noodle soup, and a “solid” condensed soup like cream of potato seem to give good results.

Procedure:
1. Teams discuss and analyze what is going to happen as the gravitational potential energy the cans have at rest at the high end of the table convert to other forms as they roll down. Then they must predict the order and write it on a sheet along with a brief summary of the reasons for the predictions.
2. Each team hands in its prediction sheet.
3. The race is run in pairs to determine win, place, and show.
4. Predictions are examined and a winning team declared (if there is one).

Wisconsin Standards:
D.4.5. Construct simple models of what is happening to materials undergoing change…

D.4.7. Describe physical events and describing changes including position…, motion over time…


Model of a Hydrogen Atom

Activity #29 above is a scale model in which the system to be modeled is sacled down tremendously to make it possible to comprehend the solar system. The model in this activity is one in which the system is scaled up tremendously in size to make the hydrogen atom’s constituents possible to visualize in a simple way.

Materials: Pin with head about 2 mm in diameter, cork in which to stick pin

Safety: Pin should be anchored in cork to avoid injuries.

A hydrogen atom has one proton and one electron. Most of the atom is empty space. The nucleus of the atom (“the proton”) is very small (its diameter= 0.0000000000000025 meter). The electron, a very light particle with a diameter too small to measure, travels around the proton in a cloud about 84,600 times larger in diameter than the proton, but the proton has 99.95 percent of the atom’s mass.

To make a model of an atom, use a pin with a 2 mm diameter head as the proton. One person holds the pin (the proton) while the other walks 42.3 meters (about 70 steps) from the proton. This is the average electron distance from the proton, but it may be closer sometimes or farther away sometimes also. The electron moves around the proton very fast as a thin cloud.

1 m (in the model) = 0.00000000000125 m (in the atom)

Wisconsin Model Academic Standards for Science:
A.4.2 When faced with a science-related problem, decide what evidence*, models*, or explanations* previously studied can be used to better understand* what is happening now
D.4.7 Observe* and describe* physical events involving objects and develop record-keeping systems to follow these events by measuring and describing changes in their properties, including position relative to another object, motion over time, and position due to forces

This IS Rocket Science:
Balloon Rocket Race

Basic principles: Jet engines, rockets, and balloons alike move forward because of thrust, which occurs because the device is losing mass at one end. To conserve momentum, which must occur in any interaction in nature, the device must move in the other direction. This happens if the device is in air, but occurs equally well in empty space. (In other words, to counter a common misconception, the escaping gas system does not push against the surrounding air as air, exhaust, etc. escape.) If a filled balloon is attached to a horizontal straw free to slide on a horizontal string and the end released, the balloon will
a. accelerate to some maximum speed determined by the difference between the force of thrust forward, the force of friction, air resistance, etc. backward, and the length of time the thrust lasts,
b. and then slow to a stop because of friction, air resistance, etc.
c. (Note: if the string is not horizontal but slightly “downhill”, gravity will help to speed up the rocket as it goes; if “uphill” it will slow it down.)

Learning objectives:
Content: momentum conservation, rocket/ jet propulsion
Skills: observing motion and analyzing different segments, asking questions, analyzing variables, proposing explanations, conducting investigations

Safety consideration:
Balloons pose a serious choking hazard. Children should use a balloon pump. Others should blow up balloons only when sitting or standing still free of distraction.

Introductory activity: exploring momentum conservation
Materials: marbles and grooved rulers

Roll first marble toward stationary second one of the same size and mass. Note transfer of motion (speed, energy, etc.).

Balloon race:
Meterials: balloons, tape, two or more (horizontal, if possible) strings with straws stretched across the room, tape to mark final positions of balloons at end of race, stop watch (if time of flight is of interest).

Move all straws on strings to one side of the room.
Tape blown up balloons to straws so that open ends are pointed toward the near wall.

On a prearranged starting signal, release balloons. Measure how far they move. Time the flight, if desired, to determine average speed.

Identify variables and conduct investigations by changing one and observing the effect on distance and/or speed.

Extensions: Try slopes or even vertical flights.

Wisconsin Standards:
C.4.2 Use the science content being learned to ask questions, plan investigations, make observations, make predictions, and offer explanations
C.4.4 Use simple science equipment safely and effectively, including rulers, balances, graduated cylinders, hand lenses, thermometers, and computers, to collect data relevant to questions and investigations
D.4.7 Observe and describe physical events involving objects and develop record-keeping systems to follow these events by measuring and describing changes in their properties, including:
” position relative to another object
” motion over time
” and position due to forces