Table
of Contents
1. Air Brakes (Air friction)
2. Air Pressure Rocket
3. Air Pressure Activities
4. Tablecloth Trick
5. Action-Reaction Rocket (on a
string)
6. Egg-drop in bottle
7. Different Sound Pitch in
Soda Cans
8. Liquid Rainbow in Straw
9. Air Resistance with
Parachutes
10. Operation Lift-Off Balloons traveling different distances
11. Air Pressure Experiments
with newspaper and straws
12. Creative Weigh-in
13. Chromatography with Markers
and Filter Paper
14. Candy buoyancy (sink or float)
15. The magic boat
16. Outrageous Ooze
(Cornstarch)
17. On the Rebound (bouncing ball)
18. Structure and function
(Bio)
19. Cooked vs. Raw Egg
20. Refraction
21. Two Forks (Center of
Gravity)
22. Gases and Gravity (baking
soda and vinegar)
23. Run-Away Pepper
24. Geodesic Gumdrops
25. Whirlpool in a Bottle
26. Creating Big Bubbles
27. Graphing Activity
1. AIR BRAKES (Amanda Dunn)
What is Needed:
2 pieces of paper
3 balloons
Ruler
1. Make an airplane with one piece of paper.
2. Hold the airplane piece of paper by the tail with its nose facing down as high as possible. Next hold the other piece of paper level with the nose of the airplane.
3. Release the two papers.
What happens to the paper? Which one touches the floor first? You may want to run this two or three time to confirm that your results are correct.
4. Now pick up the balloons and put the paper away. Blow one balloon completely up. Blow another balloon half the diameter of the first balloon. (Use the ruler to check this.) Do not blow the third balloon up at all.
5.Predict which balloon will hit the ground first, second, and third of the three balloons.
6. Hold the small balloon (Half size) and the inflated balloon. Drop them and see what happens. Repeat 2-3 times.
7. Repeat 6 using the large and small balloons.
Questions:
* Do your results make sense?
* Can you explain your results based on the friction between the balloons and the air?
Air Friction:
Friction is defined as a resisting force by an object and air that causes one object to drop slower then another object. If an object is larger in size it has more air friction against it; therefore, will drop slower than a smaller object or an aerodynamic object. In the case of the paper, the piece of paper must displace a lot more air to fall to the ground while the airplane has less air to displace so it will reach the ground first. The same is true for the balloons.
2. Toying Around
With Air Pressure and Aerodynamics Lesson Plan
Amber Vasquez
Objective: To introduce the students to a branch of physics with is aerodynamics and air pressure.
Materials: cotton swab, paper, blunt-end scissors, tape, straw, empty plastic soda bottle.
Instruction: The lesson that will be introduced to the students is a branch of physics called aerodynamics. Although the science experiment deals with the application of aerodynamics to airplanes or flying objects, aerodynamics actually relates to the effect that air has on any moving object including cars, boats, footballs, skiers, and skateboards. But included with the science activity I am going to incorporate the basic principles of air pressure. Here is some information you could use to explain air pressure:
We live at the bottom of an ocean of air called the Earth’s atmosphere. Since gravity pulls down on the atmosphere, air near the Earth’s surface is “squashed” by the weight of all the air above it. This means that there are actually more molecules in the air at sea level than there are just one mile above sea level, and a lot more than there are at the top of a high mountain. At any point in a column of air, the motion of molecules at that point causes what we call air pressure. Since molecules move in all directions, the air pressure at any point is considered to be equal in all directions. Whenever there is a difference in air pressure between two places, the air will tend to move from a place of higher pressure to a place of lower pressure.
Next, start explaining the science experiment you will do with your students. The experiment is called Toying Around With Air Pressure. In Toying Around With Air Pressure, students make an air pressure-powered rocket and try to find ways to make it go as far as possible. Students can try changing the size, shape of weight of the paper cone, the length or diameter of the straw, or the size or shape of the plastic soda bottle.
How to Do the Experiment:
1. Cut a circle about 4 cm in diameter from your paper. Cut a slit to the center as shown then shape into a cone. Trim the point to make a small hole at the top.
2. Pull off the cotton from one end of a cotton swab. Push the cotton on the other end of the swab up through the hole so that the cone stays on the swab snugly. This is your air pressure rocket.
3. Place a straw into the empty bottle and hold it in place. Use the same hand to seal the opening of the bottle as much as possible. Place the rocket into the straw.
4. Point your rocket away from your face and away from any one else. Give the bottle a hard squeeze. Your rocket should zoom.
Caution: Be sure to point the rocket away from yourself
and anyone else.
Challenge: Try using a different bottle, straw set-up, or rocket design to create an air pressure rocket that goes the farthest!
Hint: Since you learned that air will always move from an area of high pressure to an area of lower pressure. Also air can be compressed, it has a higher and higher air pressure. With these two air pressure facts you can use them to make an air pressure rocket.
Conclusion: You can make physics fun by teaching about aerodynamics and air pressure then having the students make a fun toy incorporating the concepts of aerodynamics and air pressure.
3. AIR PRESSURE RULES
Giselle de Guia
GRADE LEVEL: 3-5
PURPOSE: To demonstrate the basic air pressure rules then have them try there own air pressure projects to demonstrate the rules they just learned.
SUPPLIES FOR DEMONSTRATION: Deep container (i.e. clear bucket), clear cups, paper towel, smooth piece of cardboard, and balloon.
4 Basic Air Pressure Rules
Rule # 1
Air takes up space.
Demonstration: Place a wad of paper towel in the bottom of the clear cup. Turn the cup upside down and push it straight down into the deep container of water. The paper towel stays dry. Water cannot fill the glass because it is already filled with air. But if the cup is tilted, some air escapes and water can then enter.
Rule # 2
Air pushes on things in all directions.
Demonstration: Fill cup all the way to the rim with water. Place a square piece of cardboard over the cup making sure there are no air bubbles trapped inside the. Holding the cardboard in place, turn the cup upside down. Take hand off cardboard. The cardboard does not fall. Air is pushing up keeps the card board and water in place. Because air pushes in all directions the cup can even be turned sideways and the water won’t pour out.
Rule # 3
When air is squashed or compressed its pressure increases.
Demonstration: When air is pumped into a tire, or in this case a balloon, a lot of air is squashed into a small amount of space. Blow up balloon. There is a lot of pressure inside.
Rule # 4
Air always tries to move from a place of higher pressure to a place of lower pressure.
Demonstration: Blow up a balloon. The air pressure is higher inside the balloon than outside of the balloon. Let go of the balloon. All the air comes out. The air moved outside of the balloon where the pressure is lower.
Now introduce the next two
activities with a goal in finding which rule or rules apply to each activity.
Student activity # 1:
What's Going On Here?
Supplies for this project:
Water bottle and a
small piece of paper napkin or tissue paper
Step 1: Cut or tear the piece of tissue paper so that
is slightly larger that the opening of the bottle. Place the piece of paper on the opening.
Step 2: Try to blow the paper into the bottle! What happens? Why do you think its so
difficult?
Step 3: Give yourself a little head start by pushing
the paper partially into the bottle as shown.
Try blowing it in
again.
*Have each student try it. Lab partners will share a bottle.
*Ask students: Which rule or rules does this
project demonstrate? Discuss their answers.
The rule that
applies is rule # 2.
Student activity # 2: Toying around with air pressure ( make an air pressure rocket)
Supplies for the Air Pressure Rocket: cotton swab, paper, blunt scissors, tape, straw, empty plastic water bottle.
Step 1: Cut a circle about 4 cm in diameter from your paper. Cut a slit to the center as own then shape into a cone. Trim the point to make a small hole at the top.
Step 2: Pull off the cotton from one end of a cotton swab. Push the cotton on the other end of the swab up through the hole so that the cone stays on the swab snugly. This is your air pressure rocket.
Step3: Place a straw into the empty bottle and hold it in place. Use the same hand to seal the opening of the bottle as much as possible. Place the rocket into the straw.
Step 4: Point your rocket away from your face and away from anyone else. Give the bottle a hard squeeze. Your rocket should Zoom!
*Students can split up the project between lab partners. One student can make the rocket and one can make the launcher.
**During and after making the rocket have the students think of what rule or rules apply to the launching of the rocket. Go over the answers with them. Answer to activity problem: The two rules that apply are rules # 3 and # 4.
These Air pressure
rules and student activities were taken from the book The Best of
WonderScience, Elementary Science Activities : by American Chemical Society
and American Institute of Physics.
Published by Delmar Publishers in 1997. Pages 412, 413, and 416.
I put these three
projects together and slightly changed them to make a Physics lesson.
4. The Great Tablecloth Trick!
Meg Graber
This is a fun lesson for students from the second grade and up. Most of the kids will probably have seen a magician pull a tablecloth out from under a set table. Well now you can show them how!
Students should understand the following
For this lesson you will need
· Unbreakable plastic cups or bowls with smooth bottoms
· Rice, washers, bolts, or other objects used as weights
· Sheets of white paper (one per bowl or cup)
· A table or counter top with a smooth surface
5. Student Report
Azra Mohammed
Hypothesis:
Activity # 1
Using Newton’s third law of motion: ‘Action Reaction.’
To make a straw rocket and use a balloon to facilitate the action reaction. To test that the rocket will take off in the opposite direction when the air is let out of the balloon.
Activity # 2
A cork is floating in a jar of water. Which way will the cork move with a quick, sharp shove? What will be the first motion of the cork? Will the cork move in the direction of the shove, backward or in a direction opposite to the shove?
Procedure:
Activity # 1:
Activity # 2:
Observation: Activity # 1
The balloon rocket took off in the direction opposite to the air being released from the balloon when the paper clip was removed. Initially the rocket had great speed and then slowed down before it stopped.
Activity # 2
The cork in the jar first moved forward when the bottle was shoved and then moved in the opposite direction.
Result:
The above activities prove Newton’s third law of motion that every action has an equal and opposite reaction. The air released from the balloon makes the balloon rocket go forward. The shove of the jar makes the cork inside it rebound. The water in the jar helps to stabilize the reaction. The cork does not move in a circular motion but just forward and then backward.
6. Egg Drop
(Tammy Ritter)
Objective:
To introduce students to air pressure and its affect on objects.
Materials:
Procedure:
Follow up:
Purpose: To demonstrate how frequency affects the pitch of sound.
Materials: Soda cans, pencils
Procedure: Ask each student to bring a can of soda or juice to school prior to demonstration. Explain to the
students that the pitch of a sound is determined by how rapidly an object vibrates. Then, divide your students into
small groups equipped with their canned beverages. Have each member drink a different amount of liquid so that each
person in the group will have a different level of beverage in their can. Have each student tap the can with their pencil
while the other group members listens to the sound it creates. After each student has tapped their can have them
observe which cans have a higher pitch and which have a lower pitch. Next, have them arrange their cans in order from
the lowest to highest pitch.
Explanation: Explain to the students that sound is produced by the vibrating can, and the amount of liquid in
each can affects the rate of vibration. The cans with more liquid vibrate slower, which produces low-pitched sounds
and the cans with less liquid vibrate faster, which produces high-pitched sounds.
Materials:
The purpose of this experiment is to
challenge students to layer five liquids of different density in a drinking
straw. They will learn how to observe
and interpret data as well as learn the basic concept of density.
Preparation:
Prepare five salt solutions, each with a different density. Use the
following recipe:
Pitcher #1: 1 gallon water + 0 cups of salt + bottle of yellow coloring.
Pitcher #2: 1 gallon water + 1/2 cups of salt + bottle of green coloring.
Pitcher #3: 1 gallon water + 1 cups of salt + no coloring (clear).
Pitcher #4: 1 gallon water + 1 1/2 cups of salt + bottle of red food coloring.
Pitcher #5: 1 gallon water + 2 cups of salt + bottle of blue food coloring.
Mix the
solutions thoroughly, until all salt is dissolved. Pickling salt is preferred for this activity because it does not
have any additives and will not make cloudy solutions, but regular salt can be
substituted. Add the entire contents of
one of the small bottles of food coloring, usually sold in sets of four at the
grocery store. Clear or translucent
drinking straws must be used so that the colors of the different solutions can
be observed when in the straw. Each
student or group of students will need six small containers; five to hold the
solutions and one to be used as a waste container.
Presentation:
Do not allow students to see
how much salt is in the solutions.
Place the five pitchers in a random order. Distribute a sample of each of the five solutions to students.
Allow them to practice placing a finger over the end of a straw and
"picking up" a sample of a solution.
Direct them to
select two of the solutions at random. Draw a small portion of the first
solution into the straw. While holding
the solution in the straw, lower the end of the straw into the second
liquid. Draw a sample of the second
solution into the straw. If the first solution floats on the second, the first
is less dense. If the first mixes or falls through the second; the first is
more dense.
By making comparisons of all five
liquids and making record of each trial, student will establish an order of
density for the five liquids. As an extension, challenge students to get all
five solutions layered in the straw.
Students will also develop their
own technique for drawing a small sample of the solutions into the straw
(holding their thumb over the end of the straw, using it as a air valve). They
will be challenged to determine a technique to get all five solutions in the
straw. They will learn to lower the straw progressively lower into each
solution.
9. Air
Resistance
What Makes a
Parachute Float Slowly Down?
James Perez
Goals:
1. Student will understand that a parachute falls slowly because there is air pushing back on it.
2. Student will understand that any object that moves through the air is being slowed down by air resistance.
Objectives:
Materials: Per student
Procedure:
Challenge Phase
Assessment:
Source:
http://www.askeric.org/Virtual/Lessons/Science/Physics/PHS0002.html
Michele Pena
Subject: Science & Math
Grade Level: 2nd
Strategy: small groups
Time: 45 minutes
Objective: To teach students about Isaac Newton’s Force and Motion theory, “For every action, there is an equal and opposite reaction.” An object’s acceleration is proportionate to the amount of total force exerted on it.
Ask the students if they have ever seen the space shuttle launched into space. This is made possible when tremendous steam (from the combination of hydrogen and oxygen) is pushed backward out of the shuttle and we see by Newton’s law that the steam pushes the shuttle forward, all the way into space!
Activity: Construct balloon rockets to demonstrate the law of motion. Show how different amounts of air cause different amounts of motion.
Materials:
· Balloons of varying sizes
· Popsicle sticks
· Drinking straws
· Masking Tape
· Lengths of string (at least 10 ft)
· Rulers
· Chalkboard
Procedure:
1. Feed the string through the straw and tie Popsicle sticks for handles.
2. Have two students hold the ends of the string (flight path) and put a 2 inch piece of masking tape on the straw.
3. Have another student blow up the balloon, not tying the end, attach the balloon to the taped straw.
4. Have students release the balloons noting the distance traveled.
5. Repeat the process using different sizes of balloons (amounts of air).
Conclusion and Modification: Ask the students why different balloons traveled at different distances. Students should be able to see that the different amounts of air in the balloons cause the different distances traveled. For older students, you could have them measure the diameter of the balloon and the exact distance. You could then have them plot this information on a graph further illustrating the relationship between force and acceleration.
11. LEARNING ABOUT AIR PRESSURE
Elaine Galvery
Grade Level: 3-5
Purpose: To demonstrate the presence of air pressure in our daily lives. Students will have hands-on experience for a better understanding of how air creates pressure and exhibits power in the simple things that we do.
Supplies: yardstick, newspaper, cups, 2 straws per student, clay, and plastic drink bottles.
Activities:
1.
To demonstrate that there is air pressure pushing on us
from every
direction and that it is powerful, the teacher will place one sheet of newspaper, unfolded over a 1/8” thick yardstick on a flat surface. Make sure the newspaper is flat on the surface, letting in as little air as possible. The yardstick should extend past the surface (table) by no more than half its length.
Quickly strike the end of the yardstick that is hanging off the edge of
the table. Ask students what they think will happen:
Will the newspaper go flying into the air?
Will the newspaper tear?
Will the stick break?
What happens and what did you
learn?
The yardstick should break, demonstrating that at sea level, there is almost
15 pounds of air pressure per square inch and that means that a full sheet of newspaper, laid out flat, has nearly 9300 pounds of air on it. The yardstick breaks because of the “heavy” air pushing down on the paper. The table is also pushing back on the paper. You are literally trying to lift 9300 pounds with the yardstick. Because of the quick and sharp hit on the yardstick, the air cannot get under the paper fast enough to equalize the pressure, and the yardstick breaks.
2. To show how nature tries to equalize air pressure, give each student two straws and a small cup of water, filled about halfway. Have the students
put both straws in their mouths, but only one in the cup of water. Now,
have then suck on both straws.
What happens and what did you
learn?
When the students suck on both straws, no, to little, water should come
up the straw. As nature tries to equalize the pressures, pushing air up through the free straw is much easier than pushing liquid, so only air flows into your mouth.
A variation on this activity would be to put a small pinhole near the top of the straw and trying to suck liquid through that straw. Nothing will happen. Now have students put a finger over the hole. The liquid should make it up the straw.
3.
Another variation on this principle of
equalizing pressures so a liquid
will travel up a straw, supply students with a half filled plastic water
bottle. Have them put a straw into the bottle with enough of the straw
sticking above the top of the bottle so they can suck on it. Have
students seal the opening of the bottle with clay, so that no air can get
into the bottle. Now have students try to use the straw to get a drink of water.
What happens and what did you
learn?
When the air is sucked out of the straw, the straw collapses. In an open bottle, the air pressure outside the straw pushes down on the surface of the liquid enough to force the liquid into the empty straw. In the closed bottle, there is not enough air to press the liquid down so it cannot push the liquid up the straw. Air pressure is the result of gravity pulling the gas molecules in the air downwards.
Conclusion:
Using these easy experiments with air pressure, the student can see how important air and air pressure are in everyday activities, such as trying to drink a liquid through a straw. This is something they can do at home with their families and friends. It demonstrates the importance of air on our Earth.
Propose: to compare the weight of a paper creature with that of paper
punches.
Materials:
·Straight pin
·Small index card
·Straw
·Scissors
·2 wooden blocks of equal height and not
as wide as the length of the straw
·Paper hole puncher
·Ruler
Procedure:
·Use
the ruler to find the center of the straw and mark the spot with the marking
pen.
·Cut
1 in slits in each end of the straw. The slits should be in the same relative
position on each end.
·Divide one index card in half by folding and cutting along the fold.
·Insert the paper pieces in the slits on each of the straw to form two
flat surface that are parallel with each
other. These papers will act as weighing pans.
·Punch the straight pin through the center of the straw, leaving an
equal amount of the pin sticking out on
each
side of the straw.
·Position the two wooden blocks on a table and place the ends of the pin
on the edges of the blocks.
·Draw
your version of a space creature on half of the index card.
·Cut
out the creature and place it on one of the balance’s paper weighing pans
·Cut paper punches from the remaining
portion of the index card and continue to place them on the empty
paper
weighing until the saw is level with the table.
Results: the end holding the paper creature falls down but starts to
rise as paper punches
are
added to the opposite weighing pan. Too many punches lift the creature above
the balancing point.
Why:
The downward pull that gravity has on an object is called its weight. Placing
the
paper
creature on one side of the balance increases the weight on that side. Adding
the paper punches on
the
opposite pan begins to balance the weight of the creature. When the total
weight of the paper punches
equals the weight of the paper creature, the balance will be level with
the table. The level balance indicates
that
the pull of gravity is the same on both sides of the balance.
13. Student Report: Chromatography
By: Carrie Visscher
Materials Needed:
2 black water-soluble markers of different brands
2 coffee filters
2 drinking glasses
Eyedropper
Water in a jar
Step 1:
Make a small spot about ½ in. in diameter in the center of each coffee filter using one marker for each filter. Place a filter on top of each glass.
Step 2:
Use the eyedropper to drop water onto each ink spot. Put the same number of drops on each one to make the test fair.
Step 3:
Look closely to see what happens to the color spot from each pen as the ink dissolves in the water and spreads out.
Step 4:
Do both ink spots make the same pattern? What colors make up the black color of each marker?
Conclusion:
Chromatography is the separation of colors. In this experiment we use chromatography to see what colors are in each ink marker. The primary colors are red, blue, and yellow, so there should be a mixture of these colors. For a variation you can try repeating this experiment using markers of different colors and find out what each one is made from.
14. Will the Candy Float
or sink?
SUBJECT: Physics
and Mathematics
GRADE LEVEL: 3rd – 5TH
STRATEGY: as a class or in small groups
TIME: 10 – 20 minutes
OBJECTIVE: To teach
students about buoyancy, density and displacement. Students will be able to recognize properties that affect sinking
and floating. The discussion can also
lead into learning about Archimedes Principle of the Bouyant Force.
MATERIALS:
ü
Snickers, Milky Way, 3
Musketeers, Skittles, Kit Kat, Butterfinger and Almond Joy fun-sized candy
ü
A bowl, or a 2-liter
soda bottle cut in half
ü
Water
PROCEDURE:
|
SNICKERS |
MILKY WAY |
3 MUSKETEERS |
SKITTLES |
BUTTERFINGER |
KIT KAT |
ALMOND JOY |
FLOAT
|
5 |
14 |
21 |
26 |
17 |
20 |
17 |
SINK |
25 |
16 |
9 |
4 |
13 |
10 |
13 |
2. Give each student
or small group, one piece of each of the different types of candy.
* To make math as part of
this lesson, ask the students to make a bar graph using the predictions from
the table written up on the chalkboard.
Their bar graphs may look something like the following:
LESSON: Three
forces of nature work together to make an object float. Bouyancy is the upward force that liquids
exert against an object (Archimedes Principle). Density is an object’s mass divided by its volume. Displacement is the volume of water moved by
a floating or sunken object.
OTHER OPTIONS TO THIS
EXPERIMENT:
15. THE MAGIC
BOAT
Area of Science: Physics
Grade Level: K-3 (Ages 5-7)
Overview: This activity allows the students to make a macroscopic object (foil boat) move across the water on its own due to the breaking of surface tension by the dishwashing solution.
Materials Needed: Piece of foil, large preferably flat pan filled with water and a few drops of dishwashing/laundry detergent or soap solution.
Directions: Take the piece of aluminum paper and fold it
into a boat (preferably into a power boat shape). Fill the large flat pan with water and place the pointy side of
the boat towards the water. Now drop a few drops of soap solution directly onto
the water behind the aluminum boat and see the boat move across the water
surface.
Note: The activity
can only be performed once. If you
would like to repeat the activity, you must use a new pan of water.
Explanation of Activity: As the soap molecules in the
dishwashing liquid spreads it breaks the surface tension of the water allowing
the aluminum boat to be pushed or moved.
Website Found:
http://www.nyelabs.com/core.html?flashtarget=core.html&noflashtarget=noflash.html
16. Outrageous Ooze
Longina Burroughs
Objectives:
What do I need?
What do I do?
coloring. (Use whatever colors you
like.) Add water slowly, mixing
the cornstarch and water with your
fingers until all the powder is
wet.
3.
Keep adding water until the Ooze feels like a liquid when you're
mixing it slowly. Then try tapping
on the surface with your finger or
a spoon. When Ooze is just right, it
won't splash--it will feel solid.
If you Ooze is too powdery, add a
little more water. If it's too wet,
add more cornstarch.
4. Play around with your ooze!
·
Pick up a
handful and squeeze it. Stop squeezing and it will drip through your fingers.
·
Rest your
fingers on the surface of the Ooze. Let them sink down to the bottom of the bowl. Then try to pull them out fast. What
happens?
·
Take a blob
and roll it between your hands to make a ball. Then stop rolling. The Ooze will
trickle away between your fingers.
·
Put a small
plastic toy on the surface. Does it stay there or does it sink?
What's going on?
Your Ooze is made up of tiny, solid
particles of cornstarch suspended in water. Chemists call this type of mixture
a colloid. As you found
out when you experimented with your Ooze, this colloid behaves strangely. When
you bang on it with a spoon or quickly squeeze a handful of Ooze, it freezes in
place, acting like a solid. The harder you push, the thicker the Ooze becomes.
But when you open your hand and let your Ooze ooze, it drips like a liquid. Try
to stir the Ooze quickly with a finger, and it will resist your movement. Stir
it slowly, and it will flow around your finger easily.
Back
in the 1700s, Isaac Newton identified the properties of an ideal liquid. Water
and other liquids that have the properties that Newton identifies are call Newtonian
fluids. Your Ooze doesn't act like Newton's ideal fluid. It's a non-Newtonian
fluid.
There are
many non-Newtonian fluids around. They don't all behave like your Ooze, but
each one is weird in its own way. Ketchup, for example, is a non-Newtonian
fluid. (The scientific term for this type of non-Newtonian fluid is thixotropic.
That comes from the Greek words thixis, which means "the act of
handling" and trope, meaning "change".)
Wow I didn't know that!
Ketchup, like Ooze, is a
non-Newtonian fluid. Physicists say that the best way to get ketchup to flow is
to turn the bottle over and be patient. Smacking the bottom of the bottle
actually slows the ketchup down!
Quicksand is a non-Newtonian fluid
that acts more like your Ooze--it gets more viscous when you apply a shearing
force. If you ever find yourself sinking in a pool of quicksand (or a vat of
cornstarch and water), try swimming toward the shore very slowly. The slower
you move, the less the quicksand or cornstarch will resist your movement.
17. ON THE REBOUND
Julie Scates
See Testing the Bounce before doing
this activity.<?xml:namespace prefix = o ns =
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Topic
Patterns (height of drop/ball's
bounce)
Key Question
How does the bail's bounce compare
with the height of the drop?
Focus
Students will discover a pattern
relating the height from which a ball is dropped to the height of its bounce.
Guiding Documents
NCTM Standards
Use patterns and relationships to
analyze mathematical situations
Make and use measurements in
problems and everyday situations
Project 2061 Benchmarks
Mathematics is the study ofmany
kinds ofpatterns, including numbers and shapes and operations on them.
Sometimes patterns are studied
because they help to explain how the world works or how to solve practical
problems, sometimes because they
are interesting in themselves.
· Measurements are always likely
to give slightly different numbers, even if what is being measured stays the
same.
· Graphical display ofnumbers may
make it possible to spot patterns that are not otherwise obvious. such as
comparative size and trends.
Math
Estimation
Measurement
length Graphs
bar and line Patterns
'¼
Integrated Processes
Observing
Predicting
Collecting and recording data
Comparing and contrasting
Generalizing
Science
Physical science force and motion
Materials
For each group:
golf ball
meter stick
small pieces of paper
Background Information
Students intuitively know that the
ball will drop to the ground. The force of gravity is pulling the ball toward
the Earth. Students also
intuitively know that the higher the
drop, the higher the bounce; the lower the drop, the lower the bounce. The
attention here is on the
pattern formed from the data.
We want students to get excited about
finding patterns. There is a relationship, a pattern between the height of the
drop and the
height of the bounce for a particular
ball striking a particular surface. With the kind of data being gathered, a
line graph is often used to
show the results. However, a bar graph
is more understandable for younger students. If they compare the differences
in bounce
heights on a bar graph, students
should find they form fairly consistent increments. They can then use this
incremental distance to
predict the bounce height for a drop
from 120 centimeters.
Measurement is never exact. A
measurement can always be taken to another, more precise decimal place.
Measuring a ball in motion is
even more difficult. Students should
realize that their measurements are approximate.
Management
1.
Divide the class into groups of three.
2.
To test the bounce, hold the meter stick vertically or tape it to a wall
or pole. Hold the ball so its bottom is even with the
designated height and let it drop;
do not throw or push. By standardizing the way the ball is handled, a variable
is being controlled.
3.
To measure the bounce, find the distance from the surface to the bottom
of the ball at the height of its bounce.
4.
Use a concrete surface if possible.
5.
Although the graph starts with zero and rises to 100, more accurate
measurements are likely if students conduct the tests in
reverse order, starting with the
100-centimeter drop.
6.
Students should conduct several trials at each height because it
requires practice to read a measurement when an object is in
motion. When they are getting fairly
consistent readings, they are ready to record the result. Students should read
the
measurement at eye level.
7.
To measure the graph increments, use a small piece of paper to mark the
difference in bounce height between 0 and the
20-centimeter drop height (A). Then
move the paper up to mark the difference in bounce height between the
20-centimeter and
40-centimeter drop height (B).
Continue until all increments have been compared. The marks that were made
should be fairly close
together. Have students find the
middle of the range of marks and mark that distance on the graph to predict the
unknown bounce
(C).<?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" />
A.
0 20 40
B. C.
WOI
0 20 40 60
(The following is offered for those
students ready for more independent investigations.)
Open-ended: Ask the Key Question and
have groups devise their own plan for answering it. Students should recognize
the variables to be
controlled-type of ball, kind of
surface, and how the ball is released. They also need to choose an appropriate
graph for the data.
Procedure
1.
Give each group a golf ball and ask them to drop it (informally and with
no measuring devices) different distances from the floor.
Ask for their observations. "How
do you think the height of the drop is related to the height of the bounce?
Let's find out."
2.
Distribute the activity page and instruct students to record the type of
ball and type of surface (controlled variables).
3.
Give each group a meter stick and have them go to the locations where
they will be performing the investigation.
POPPING WITH POWER
4. Direct students to record, in the first column, the drop heights
indicated on the graph. Have them estimate, then test and
measure the height of the bounce,
continuing until they have completed the table.
5. Instruct students to make a bar graph from the data. Discuss
their initial observations of the bar graph.
6. Ask, "Is there a pattern to how the graph is
organized?" [counting by 20's] "Then what would be the drop height
for the
dotted bar?" [120 centimeters~
Have students label the dotted bar.
7. Ask, "If the starting height is 120 centimeters, how can we
predict the height of the bounce?" Give students time to think
about this. Use one or more of
their suggestions. Continue the discussion by asking, "If the
height-of-drop bars increase
consistently, do the bounce
heights also increase consistently?"
8. Show students how to mark the distance between bounce heights
(see Alanagement 6) and find the middle of the range. Have
them use their small paper to mark
the predicted height of bounce for 120 centimeters. This is a prediction based
on a pattern.
They may want to fill in some of
the cross bars at the top to help them determine the number of centimeters.
9. Instruct students to record data at the bottom of the activity
sheet, then test and record the actual bounce. Hold a concluding
discussion.
Discussion
1. What did you observe when you first dropped the balls (before
doing the investigation)? [They fall to the ground (gravity).
They bounce back up, but not as
high. The higher you start, the higher the bounce.~
2. What does the bar graph tell us?
3. How do your group's
results compare with others? (Variations in the accuracy of measurements and
how well variables are
controlled can cause differences.)
4. How can we make a height-of-bounce prediction for a 120-centimeter
drop height? (Have students look for patterns in the bar
graph.)
5. 1 wonder... [how the second bounce compares to the first bounce,
if the second bounce also forms a pattern, if substituting
another kind of ball will also
make a pattern, how another type of surface might change the pattern, etc.]
Design an investigation
to find the answer to one of these
wonderings.
Extension
This activity is one in a series
that tests the different variables affecting a ball's bounce. See also Have a
Bail and From the Ground
Up.
Teacher Resource
Taylor, B.A.P., Poth, J.E., and
Portman, D.J. Teaching Science With Toys: Physics Activities for Grades
K-9. Terrific Science
Press. Miami University
Middletown, Middletown, OH. 1994.
(See "Bouncing
Balls," pgs. 73-77.)
Casandra Campbell
SCI 210
(Modified Version)
Purpose:
The purpose of this activity is for children from 3rd to 12th grade to explore the functions of their hand, and what it would be like if the structure was changed. This experiment will allow students to examine what specific structures in a hand are necessary to carry out daily activities. They will see how hard it would be without these special structures like thumbs and pointer fingers.
Materials:
Tape, cups, Popsicle sticks (or unsharpened pencils), rice, spaghetti, a deck of playing cards, and cereal (ex. Cheerios). If there is a chalk or dry erase board at the front of the room it is preferable.
Activity:
* I found this experiment in the Wonder Science: Volume 2 book that I purchased for SCI 211 in spring quarter. I used the basic idea of the experiment above called “Structure and Function Come in Handy” but I modified it to create my own experiment.
19. Christine Monte
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1. Spin each egg in turn on a plate. The egg that continues to spin for a longer time is the cooked one. 2. Now spin the eggs again, then quickly stop both of them. Then let go of both eggs. You will see that the cooked egg stays still but the raw one starts spinning again. Why? |
20. Refraction (Grades
3 & 4)
Materials:
Plastic Cup
Coin
Water
Refraction:
Refraction is the
bending of light as it passes between materials of different density.
Instructions:
Experiment #1:
Experiment # 2:
Observe that the stick appears bent at the
point in enters the water
Explanation: As
light passes from one transparent medium to another it changes speeds and bends.
21. Two Forks Experiment: Center of Gravity
Valery
Walker
Material list:
One cork such as wine bottle cork
Two metal dinner forks, preferably identical.
Toothpicks
One glass
Matches
Assemble:
To assemble takes some practice and lots of patience! It is a trial and error kind of experiment.
Poke the two forks symmetrically and firmly into the cork so that the handles of the forks form about a 90-degree angle.
Poke the tooth pick carefully into the cork; take care the toothpick does not break at the tip when you poke it into the cork.
Now put the toothpick on your finger, and try to balance the above assembly on your finger. If the angle of the forks is suitable, you should find a point on the toothpick that you can balance the forks. Mark this point.
Now try to balance the assembly on the rim of the glass. It should balance at about the marked point.
Light the toothpick at the uncorked end and watch the toothpick burn away. The burning will stop once it hits the glass rim, but the fork assembly continues to be balanced at that point.
Physics explanations:
Center of Gravity of any object is the point about which you can balance the object as if all the masses were concentrated or gathered at this point. In other words, the net torque of all the masses of the object about this point is zero, regardless the shape of the object. In a uniform gravitational field, such as the classroom, the center of gravity and center of mass are located at the same point. The center of gravity does not have to be on the object, it can be in the open space. For instance, the center of gravity of this fork assembly is in between the forks in the empty space.
How do you make it stable? When you try to balance an object, if the point of support, the pivot point, is not at the center of gravity then the object will rotate either clockwise or anti-clockwise depending on which side has more torque. However, if the pivot point is on the same vertical line as the center of gravity, then the object, no matter what shape, is going to balance. It will be stable if the center of gravity lies below the pivot point. If the center of gravity is above the pivot point, even a slight disturbance will pull it off balance. You can imagine that this is like a simple pendulum where the center of mass (the ball at the end of the pendulum) swings below the pivot. If the pendulum's ball is pulled up a little, it will try to return to its most stable position with minimum potential energy. The pendulum will continue to oscillate about the pivot point until all its kinetic energy is lost to friction and it will settle down to the position with least potential energy. In our case if you want to have a stable situation, the center of gravity of this assembly has to be below the pivot point. The pivot point is where the toothpick rests on the rim of the glass. The actual center of gravity must lie in the empty space between the two forks and below the pivot point to achieve stability.
22. Gases and Gravity
Randi Lee
Materials: A small bottle
Baking Soda
Balloons
Funnel
Vinegar
Procedure:
1) Use the funnel to fill the balloon with 2 tablespoons of baking soda. Then pour 2.75 cm of vinegar into the bottle.
2) Slip the opening of the balloon over the mouth of the bottle.
3) When the balloon is securely attached to the bottle, hold the balloon upright so that the baking soda spills into the vinegar.
The mixture of baking soda and vinegar produces carbon dioxide. The gas puts pressure on the balloon and inflates it. The gas takes up much more space than the solid and the liquid, so it inflates the balloon. A similar thing happens in a volcano. When rock inside the earth melts, gases are produced. Gases take up far more space then the solid or liquid ingredients that produced them. The gases are trapped underground until their pressure grows so great that they blow their way out of the ground.
-Take the inflated balloon out from the bottle and tie it up. Get a second balloon and blow it up the same size as the first balloon. Then get a third balloon and pump it up with an air-pump.
-Drop all three balloons at the same time and height, then watch which one will reaches the floor first.
23. Frightened Run-Away Pepper
Kendra Smart
Purpose:
This experiment helps explain the
“sticky” force between two objects, known as cohesion. Cohesion is the force that holds material
together. This attraction occurs
between atoms and molecules.
We all know that
glue and tape have the capability to stick two objects together. These adhesives cause objects to cohere or
adhere together. Other examples are: rain on a car windshield, dust to a ceiling
fan, or gum to mom and dad’s carpet.
This experiment provides a K- 6th grader fun and a less
sticky situation with mom and dad.
Experiment:
Supplies: dish, pepper, dishwashing detergent
1. Fill the dish with
water (about 3/4ths full).
2. Scatter pepper over
the entire surface area of the water.
3. Squeeze dishwashing
detergent into the center of the water and pepper display.
4. Watch what
happens!!!
Results:
The pepper stays
scattered all about the water because the pepper is evenly pulled by the water
from all directions. When the detergent
is placed in the water, it reduces the cohesiveness between the water and the
pepper. It reduces the pulling action
on the pepper and it appears to run away.
The water around the edges (untouched by the detergent), still has its
full pulling strength. So this
attraction of cohesion decreases as the distance between particles increases.
24. Geodesic Gumdrops!
Presented by Janet Ahn
From Science Explorer
An Exploratorium-at-Home Book
By Pat Murphy, Ellen Klages, Linda Shore, and the Exploratorium
http://www.exploratorium.edu/science_explorer/geo_gumdrops.html
Grade Level: 3rd Grade and Up
Objective: This experiment introduces students to some basic elements of physics, tension and compression using gumdrops and toothpicks.
You could use bits of rolled up clay or caramel, partially cooked beans, or any other material with the same consistency and shape and size.
The consistency of some of the gumdrops aren’t quite the same: two different brands of gumdrops and one was on the stale side—this experiment might not work as well with materials that are too stiff.
Instructions: Begin by reading the worksheet and building different shapes with the gumdrops and toothpicks. After your students finish constructing their gumdrop structures, here is an example of the explanation of the lab (it can be simplified or more elaborate, depending on the grade level. This is an example of an explanation for 3rd to 4th graders taken from the website with slight modifications):
Ok so when you leave your gumdrop structures
alone, they look like they are standing absolutely still. But their parts are
always pulling and pushing on each other. Structures remain standing because
some parts are being pulled or stretched and other parts are being pushed or
squashed. The parts that are being pulled are in tension. The parts that are
being squashed are in compression.
Sometimes you can figure out
whether something is in tension or compression by imagining yourself in that
object's place. If you're a brick and someone piles more bricks on you, you'll
feel squashed you’re in compression. If you're a long steel cable attached to a
couple of towers and someone hangs a bridge from you, you'll feel stretched --
you're in tension.
Some materials -- like bricks --
don't squash easily; they are strong in compression. Others -- like steel
cables or rubber bands -- don't break when you stretch them; they are strong
under tension. Still others -- like steel bars or wooden toothpicks -- are
strong under both compression and tension.
As you've probably already
discovered, squares collapse easily under compression. Four toothpicks joined
in a square tend to collapse by giving way at their joints, their weakest
points. A square can fold into a diamond when you press in on one of its
corners.
Observe when you make a
toothpick triangle, the situation changes. The only way to change the angles of
the triangle is by shortening one of the sides. A triangle with equal leg lengths will have equal angles for all
its angles. (Math: Equilateral Triangle) So to make the
triangle collapse you would have to push hard enough to break one of the
toothpicks.
If you want to, you can use your
gumdrops and toothpicks to build some strong structures that are made by
combining triangles and squares. The pattern on the left is one that's similar
to some used in modern bridge design. You can make a very big structure out of
squares and cubes, but it'll be wiggly and will probably fall down. If you try
to make a structure out of only triangles and pyramids, it won't be wiggly, but
you'll probably run out of gumdrops and toothpicks before it gets very big. A
4-sided pyramid has a square on the bottom and triangles on all 4 sides. When
you make a structure that uses both triangles and squares, you can make big
structures that are less wiggly.
Build a square, and then poke a
toothpick into the top of each corner.
Bend all 4 toothpicks into the center and connect them with one gumdrop,
to make a 4-sided pyramid.
Extension: With your students you can look for other triangles in structures around you may give you ideas for other designs you can build with gumdrops and toothpicks.
25.
Whirlpool in a Bottle
Tegan Murdock
Purpose:
To teach students about surface tension and some of the reasons why water can do some of the things it does.
Supplies:
Two 2 liter soda bottles for each group
Duck tape
Water
Glitter (optional)
Food coloring (optional)
Procedures:
Explanation:
What should happen if the bottles were tapes together properly, and the water is given a good enough starting spin, is the water forms a whirlpool (vortex) inside the bottle. The reason for this is water’s high surface tension. Surface tension is the willingness of molecules of a substance to want to be together. The higher the surface tension, the more the molecules want to stick to each other. This stickiness is what causes water to form into drops, or spheres, rather than spreading out. When you start spinning the water in the bottles, you force the water to the inside edge of the bottle and because water wants to stick together, it stays on the inside edge, creating a hole for the air in the bottom bottle to escape to the top bottle.
Things to think
about:
-If you don’t spin the water in the bottle, what happens? Why?
-Can you change the direction that the water spins in? Why or why not?
-If you were to change the shape of the opening between the two bottles (such as taping one
mouth closed and cutting a new opening) what would happen? Why?
*You can also see surface tension at work by placing water drops on a penny. How many drops can you place on a penny before the water spills off? Have the students guess before hand and see who got the closest.
26. Creating Big Bubbles
Sarah Rosario
Materials:
Bubble mix
Assortment of plastic lids of different sizes
Straws
Preparation of Bubble Mix
6 cups water (Distilled is best)
¾ cup corn syrup ( Karo Light)
2 cups Dawn (or Joy) dish washing liquid.
Mix together. Let set 4 hours
Step 1
Put bubble mix into the lid until the mix comes just up to the edge.
Step 2
Dip the straw in the cup of the bubble mix to get the end of the straw wet. Next place one end of the straw into the bubble mix in the lid. Keeping the straw in the mixture, slowly blow into the straw.
Step 3
Once a bubble starts to form, you have to position the end of the straw so that you can keep blowing air into the bubble. Keep the wet part of the straw in contact with the surface of the bubble.
Conclusion:
Water bubbles do not last very long because the forces between water molecules tears these bubbles apart. Using liquid soap reduces these forces and form bubbles.
Liquid detergents are good at reducing the forces between water molecules and letting bubbles form. Detergent molecules will cover the surface of a bubble and let it expand a great deal without breaking.
Purpose: This is a graphing activity
that should be done in preparation for physics activities that involve graphing
data. This activity can also be used
for math and art. This activity will
turn your students into “point-plotting-pros.”
Activity
How to poke out the holes:
Do
not poke out all of the holes; poke out only the holes indicated on your design
directions. Place your card on a piece
of porous material and pole out the proper holes with a sharp, metal point.
How to thread your needle:
Cut
off 3-4 feet of thread and thread your needle.
Do not tie a knot. Arrange the
thread on the needle so that the first two-thirds is double and the last
one-third is single. Only single thread
may appear on the front side of the card; when you run out of single thread,
pull your needle away from the card to produce more single thread.
How to start your design:
Start
your design by pushing the threaded needle through the hole next to the first
number on the design directions FROM THE NUMBERED SIDE TO THE BLANK SIDE. Pull the thread through the hole until an
inch remains and tape in down on the numbered side. Be careful not to tape over any of the nearby holes or numbers
that you will be using.
How to complete your design:
Continue
to follow the numbers in the same order as they are arranged in each column of
the design directions. Each pair of
numbers in a column will produce one segment of the design on the front of the
card. When you reach the bottom of one
column, go to the top of the next column on the right. If all the directions for a design are not
contained on a single page, complete a;; the columns of numbers on one page
before sewing any numbers on the following page. Continue in this manner until you reach the last number.
What to do when you run out
of thread:
When
you run out of thread, or need to change the color of the thread, tape the end
of the thread down on the numbered side, rethread your needle, and start again
at the next hole indicated on the design directions.
When to change the color of
your thread:
Use
the same color of thread throughout the entire design or change the color
beginning with the number preceded by an asterisk (*) on the design directions.
Avoid these common mistakes:
1.
Sewing
around the edge of the card.
2.
Poking
out holes that tare not used. A
different set of holes is used for each design.
3.
Skipping
a number. If you skip a number, the
design will begin to appear on the numbered side of the card.
4.
Starting
the design on the wrong side of the card.
Card
to be used for these designs.
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Design
1
(1,6) (6,11) (9,14) (13,12) (10,15) (7,8)
(6,9) (9,6) (14,11) (18,13) (15,10) (12,7)
(7,8) (10,5) (13,12) (17,12) (20,15) (13,8)
(2,7) (5,10) (8,13) (12,13) (15,10) (8,7)
(3,8) (0,5) (7,12) (11,14) *(14,1) (9,6)
(8,7) (5,10) (12,13) (16,11) (11,6) (14,9)
(9,6) *(6,19) (11,14) (14,11) (12,7) (15,10)
(4,9) (9,14) (6,11) (11,6) (13,2) (10,5)
(6,9) (8,13) (5,10) (12,7) (12,3) (15,0)
(9,14) (7,18) (10,15) (13,12) (13,8) (10,5)
(8,13) (8,17) (5,20) (12,13) (14,9) END
(7,8) (7,12) (10,15) (13,8) (11,4)
(8,7) (6,11) *(19,14) (14,9) (11,6)
(7,12) (9,16) (14,11) (11,14) (6,9)