2011-2012
Sample Projects in
Physical Science
Curriculum and Instruction
Division
Science, PE, and Health
Department
Sample Projects
Physical Science Grade 8
Unit Topic
Unit 1 Motion
Sample Project
Mousetrap Catapult
Paper Roller Coasters
Unit 2 Forces, Part A
Balloon Powered Car
Mousetrap Powered Car
Unit 2 Forces, Part B
Designing a Submersible
Building a Cartesian Diver
Unit 3 Astronomy
Model of an Asteroid (Edible)
Solar System Mobile
Unit 4-5 Properties,
Constructing a Lava Lamp
Physical Changes in Matter Snow Globe
Standards
2a, 2b, 2c, 2d,
2e, 2f
2a, 2b, 2c, 2d,
2e, 2f
2a, 2b, 2c, 2d,
2e, 2f
8a, 8c, 8d
4e
4e
3b, 3d, 8a
“Science is a great game. It is inspiring and refreshing. The playing field is the
universe itself.”
Isidor Isaac Rabi (1898-1988) U. S. physicist. Nobel prize 1944.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Hand-out #1
Oh my goodness! Edible Asteroids!
Introduction:
Asteroids are rocky or metallic objects, most of which orbit the Sun in the asteroid belt between
Mars and Jupiter. A few asteroids approach the Sun more closely. None of the asteroids have
atmospheres.
Asteroids are also known as planetoids or minor planets.
Asteroids whose orbits bring them within 1.3 AU (121 million miles/195 million kilometers) of the
Sun are called Near-Earth Asteroids (NEA) or Earth-Approaching asteroids. These asteroids
probably came from the main asteroid belt, but were jolted from the belt by collisions or by
interactions with other objects' gravitational fields (primarily Jupiter).
About 250 NEA‟s have been found so far, but many, many more exist. The largest known NEA is
1036 Ganymede, with a diameter of 25.5 miles (41 kilometers). According to astronomers there are
at least 1,000 NEA's whose diameter is greater than 0.6 miles (1 kilometer) and which could do
catastrophic damage to the Earth. Even smaller NEA's could cause substantial destruction if they
were to collide with the Earth.
Asteroids vary in composition. Most asteroids consist of water (ice), frozen carbon monoxide mixed
with rock, carbon, nickel, and metallic iron mixed with iron-silicates and magnesium-silicates. Two
types of materials on asteroids appear to be attractive for mining - metals and volatiles. Both of
these are essential for space travel. The cost of launching any material from the Earth is extremely
high, so useful materials which are already in space can be very valuable.
Objective: Students will create, map and core a model of an asteroid that is edible.
Materials: (This will make one large or two small “asteroids” for about 10 students)
❑ 1 large package of chocolate sandwich cookies ❑ 10-20 grapes (depends on size of grapes)
❑ 1 large bag of marshmallows
❑ 1 stick of margarine
❑ 40 peanuts
❑ 1 large microwaveable bowl
❑ 2 containers to hold crushed cookies
❑ 1 heavy glass or other object to crush cookies
❑ microwave
❑ spatula
❑ waxed paper
❑ refrigerator
❑ apple corers, knives, or cork borers
❑ toothpicks
❑ small tabs for labels
❑ Student Worksheet
❑ metric ruler
❑ pens/pencils
Pre-Activity Questions:
1. Why would we want to go other places to mine materials (iron, nickel, etc?
2. If the resources of an asteroid are needed to support a deep space exploration mission, where
would be a better place from which to launch a resource mining expedition: Earth, a space
station, a lunar base, other? Why?
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Day 1 Create the Edible Asteroids
Recipe
1. Remove filling from approximately 8 cookies, crush cookies into fine particles and set aside on
waxed paper for step 7, save filling.
2. Crush remaining cookies (with fillings) into medium-large pieces (add filling from step 1).
3. Mix grapes and peanuts with crushed cookies.
4. Place margarine and marshmallows in microwaveable bowl and melt thoroughly, stir.
5. Combine marshmallow mixture with cookie mixture, blend gently but thoroughly.
6. Using lightly buttered hands, gather the gooey mass into an “asteroid” shape, add “impacts” or
“collision fragments” by making indentations in the warm mass.
7. While still warm, roll the “asteroid” in crushed chocolate cookies (this creates a regolith or soillike surface layer), immediately wrap firmly in waxed paper.
8. Refrigerate overnight.
Day 2 Core and Mine!
Use the worksheet on the next page. Make sure you clean up after.
With your readings on the composition of asteroids, which part of your model could correspond
to…
a. frozen ice?
b. solid carbon monoxide?
c. carbon?
d. zinc?
e. iron?
Activity adapted from NASA Educator Resources
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Project: A Solar System Mobile
In this project, you will create a mobile of the solar system, including the
mi
Materials:
A round piece of cardboard about 1 ft across (the cardboard from a frozen
pizza works well)
Lots of colors of oak tag (or construction paper)
Scissors
Tape
String
Pencil, crayons, or markers
A compass (for making circles)
Procedure:
Find the center of the large cardboard circle by drawing a line
from top to bottom and a line from right to left. Where these
two lines meet is the center of the circle. This will be the position
of the Sun.
Using a compass, draw the orbits of the 9 planets (draw circles
around the center of the piece of cardboard).
The first 4 planets orbit relatively close to the Sun, then there is a
gap (this is where the asteroids orbit). Then the last 5 planets
orbit very far from the Sun.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Using an awl, the sharp point of scissors, or a large nail, punch a
series of holes in the cardboard. First punch a hole in the center
(this is where the Sun will hang). Then punch one hole
somewhere on each circle (orbit); a planet will hang from each
hole.
Cut circles from oak tag to represent the Sun and each of
the planets. Since the range in size of the Sun and the
planets is far too large to represent accurately, just make the
Sun the biggest. Make Jupiter, Saturn, Uranus, and Neptune
a bit smaller than the Sun and of comparative sizes. Make
the remainder of the planets much smaller. Saturn has
beautiful rings.
Write the name of each planet on its back.
Tape a length of string (these can be of different lengths) to
each planet (and the Sun).
Lace the other end of each string through the correct hole in
the large cardboard circle (Mercury goes in the inner orbit,
Venus goes in the second orbit, Earth goes in the third, etc.).
Tape the end of the string to the top side of the cardboard.
After all the planets (and the Sun) are attached, adjust the
length of the strings so that the planets (and Sun) all lie in a
plane.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
To hang your model, tie three pieces of string to the top of
the cardboard - then tie these three together. Tie them to a
longer string (from which you'll hang your model).
You now have a model of our solar system.
From: http://www.enchantedlearning.com/crafts/astronomy/solarsystemmodel/
Questions:
1. In what ways is this model an accurate representation of the solar system? Identify
at least three ways.
2. What are limitations of this model? Name at least three.
3. How can this model be improved so it more accurately represents the solar system?
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Name: ______________________
Period No. ____ Date: __________
THE MOUSETRAP CATAPULT: Designing a Catapult
Introduction:
Imagine yourself living as a warrior in the 1600, the time of Galileo. You find yourself
inside a walled castle, but instead of firearms, you and your fellow warriors are using an
“odd-looking,” monstrous device, a giant catapult!
What exactly is a catapult? A catapult is a machine of war meant to fling some
sort of projectile. Though the term may be applied to modern weapons that hurl their
payloads, it is usually understood to refer to a specific type of metal and wooden
machine popular during the Middle Ages in Europe. You probably have made a simple
catapult when you tried to shoot a piece of eraser at a classmate using a ruler.
Today, we will make a catapult from a mousetrap, some duct tape, a plastic
spoon, and some popsicle sticks. The projectile would be a marshmallow. We will be
using both Math and Science to figure out if the length of the catapult‟s arm influences
the distance to which the marshmallow could be flung! This is one fun way to use Math!
MATERIALS [per group of 2-3]:
Erasers
Mousetrap
Duct Tape
Plastic Spoon
Ruler
Marshmallow
Meter stick
Chalk
PROCEDURE:
A. Constructing the Catapult and Doing the First Trials
1. Construct the mousetrap catapult according to the directions given in the
Attachment [pages 3-4].
2. Measure the length of the catapult arm in cm. Write this down inside the Data Table
[second column].
3. Test your catapult outside. Measure how far [distance in m] you could throw a
marshmallow using the catapult. Do three trials and calculate the average.
B. Reconstructing the Catapult for a Longer Arm [+3 cm]
1. Remove the spoon and lengthen the catapult arm by 3 cm using the Popsicle stick.
2. Test your catapult outside again. Measure how far [distance in m] you could throw a
marshmallow using the catapult. Do three trials and calculate the average.
C. Reconstructing the Catapult for a Longer Arm [+6 cm]
1. Remove the spoon and lengthen the catapult arm by 6 cm using the Popsicle stick.
2. Test your catapult outside again. Measure how far [distance in m] you could throw a
marshmallow using the catapult. Do three trials and calculate the average.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
DATA TABLE:
Spoon Length
[ _______ cm]
Arm Length
[_______ cm]
Arm Length
[_______ cm]
Trial 1
Distance? ________
Distance? ________
Distance? ________
Trial 2
Distance? ________
Distance? ________
Distance? ________
Trial 3
Distance? ________
Distance? ________
Distance? ________
AVE
GRAPH: Construct a line graph, distance on the y-axis and arm length on the X-axis.
Draw a line of best fit.
Questions:
Questions:
1. Did manipulating the length of the catapult‟s arm affect the distance of the throw?
2. How would you redesign your catapult so it can throw a marshmallow the farthest
distance?
3. How does the catapult demonstrate the three laws (Newton‟s) of motion?
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Directions for constructing the catapult:
1. Have an adult help you pull back the
mousetrap lever. Place the rubber band
around the base of the mousetrap and the
lever to hold the lever in place. Be careful!!!
2. Fasten one of the erasers to the mousetrap
using a piece of duct tape. The long end of
the eraser should be up against the fulcrum
of the mousetrap.
(A thick wad of paper of the same size can
be used as an alternative for the eraser).
3. Tape a second eraser on top of the first
eraser so that the second eraser is slightly
over the fulcrum (the point at which the
metal bars move). Place tape around both of
the erasers.
4. Carefully remove the rubber band from the
lever, and slowly bring it to stand next to the
erasers.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
5. Tape one of the Popsicle sticks to the
lever so that it is perpendicular with the
lever. This will support the catapult arm.
6. Tape another Popsicle stick to the lever
so that it is parallel with the lever. This will
extend the arm of your catapult.
7. On the end of the second Popsicle stick,
rubber band or tape your plastic spoon.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
8. Your catapult is ready for use! When using
the catapult, always make sure to hold down
the base.
Additional Questions:
1. Make a diagram of your catapult below. Label:
a) the point of greatest kinetic energy
b) the point of greatest potential energy
c) where potential energy transforms to kinetic energy
2. What form of energy is used in a catapult?
3. How did you increase the accuracy of your catapult?
Adapted from activities at http://www.life.uiuc.edu/boast1/sciencelessons/levers.htm and
http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/cat.htm
Created for the GREAT science teachers of TRUSD by G. Myers 2010
PAPER ROLLERCOASTERS
Introduction:
For many people, there is only one reason to go to an amusement park: the
roller coaster. Some people call it the "scream machine," with good reason. The
history of this ride reflects a constant search for greater and more death-defying
thrills.
How does a roller coaster work? What one may not realize is that the coaster
has no engine. This is hard to imagine when a person can cruise down the track
of a roller coaster at 60 miles an hour! As the car is pulled to the top of the first hill
at the beginning of the ride it picks up all the energy it needs to complete the
ride. After the first ascent, the coaster must complete the ride on its own. A rider
is not being propelled around the track by a motor or pulled by a hitch. The
conversion of potential energy (that is built up as the ride is taken up the first hill)
to kinetic energy is what drives the roller coaster, and all of the kinetic energy
that is needed for the ride is present once the coaster descends the first hill.
Remarkable isn‟t it?
Objective: Each team will design a rollercoaster from a fixed track length that can
carry one marble (simulates 100 paying customers!) to completion without flying off the
track. Each team will calculate the total energy of their rollercoaster and determine
which group has the coaster that if built in real life would be the most fun!
Permissible Materials:
Tape
Poster Paper (Two Sheets)
Sticks and piece of string
(1 m long)
Support Stand
Mar
Glue
Your teacher may allow other materials for supporting the coaster, please consult your
instructor. All tracks should only be made of paper.
Rules:
Not more than the two sheets of paper provided can be used in making
the tracks.
Marble (100 paying customers) must complete the ride from start to finish
without falling off.
For the project to be graded all mathematical computations of speed
and acceleration must be completed and data table submitted.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
PROCEDURE:
Two inches
across = total
width
Width of track is
one inch and
each folded flap
is 0.5 inch
1. Cut long strips of paper an two inches wide. Fold each side to make flaps that are half an
inch wide. This will be the roller coaster track. See template above.
2. Cut notches along each folded flap. Space the cut notches every one inch. This will allow
you to twist the tracks into different shapes. See figure above.
3. Assemble your roller coaster. For added fun (and points), you can include the following
designs in your roller coaster:
Funnel
Twists
Corkscrew
Free Fall and Catch
*Please see the Appendix for a sample of a completed product.
Part B. Computing for Potential Energy, Velocity and Acceleration
1. Start by measuring the height of your rollercoaster‟s first lift (where you will initially
place the marble). This height should be in meters (use a meter stick!). You may use a
ruler (measure in cm) and just divide the value you get by 100 to have the
measurement in m.
2. Measure the mass of your marble in grams (use a triple beam or electronic balance).
Created for the GREAT science teachers of TRUSD by G. Myers 2010
3. Calculate the PE of your rollercoaster by using the formula below:
4. Identify FOUR points (A, B, C, and D) along the track of your rollercoaster (these points
have to be as widely spaced apart as possible, with the last point at the very end of the
track). Use the piece of string and a ruler (measure in cm) to determine the length of
the track along these points.
5. Complete the data table below:
POINT
Distance from Previous
Point
Time Elapsed since previous
point*
Average Velocity**
A
B
C
D
(last point
on track)
*Measure the time it takes for the marble to pass by the previous point to the next point.
It is recommended you do three measurements and take the average.
**Average velocity is distance divided by time
Source: http://www.learner.org/interactives/parkphysics/coaster.html
Created for the GREAT science teachers of TRUSD by G. Myers 2010
6. Calculate the…
o Total length of roller coaster track: __________ m
o Total time marble takes to travel entire roller coaster length: ________ s
o Average velocity: __________________________
o Kinetic Energy of the roller coaster:
7. Total Energy of Roller Coaster:
Total Energy for your coaster is KE ______ + PE _________ =
_______ Joules.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Appendix A Roller Coaster Sample Picture
Picture from www.paperrollercoasters.com
Students from Norwood JHS working on their roller coaster project…
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Appendix B Roller Coaster Rubric
1. Construction and Adherence to Guidelines
Excellent
(21-25)
Average
(16-20)
Poor
(11-15)
a. All guidelines were strictly followed.
b. Construction is sturdy. Roller coaster does not
need repeated adjustments.
2. Marble‟s Travel
a. In five trials, marble completed the track.
3. Elements of Design
a. The track consists of various elements: twists,
funnels, corkscrew, free-fall and catch, etc.
b. The roller coaster is aesthetically appealing.
c. The roller coaster would provide a fun and
exciting ride.
4. Calculations
a. All calculations were completed.
b. All calculations were accurate.
TOTAL:
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Balloon-Powered Car
Introduction:
Newton‟s third law is probably the most famous of the laws of motion. It states
that…”For every action there is an equal and opposite reaction.” The law is
apparent in many situations…a diver jumping off a diving board, the paddling
of a person in a boat, the recoil of a gun.
In this project, you will design and create a car propelled by a balloon. The 3rd
law is utilized to propel the car into movement. As the gas escapes from the
balloon, the car moves forward.
GOAL: To design and build a balloon-powered car that can move straight and
fast!
Materials:
2 Balloons (provided by teacher)
Wheels (cd‟s, toy wheels, bottle caps)
Cardboard
Straws
Sticks (axles)
Guidelines and Instructions:
1. The chassis (car‟s body) can be any size, shape or form. It must be
made from cardboard (other materials may be allowed).
2. The only source of power must come from the gas escaping from the
balloon.
3. Any number of exhaust pipes (straws allowing gas to escape) can be
used.
4. The wheels can be made of any material (cd‟s, bottle caps, toy wheels,
etc). Be creative!
5. The car must travel straight.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
You can check a step-by-step video at
http://sciencesquad.questacon.edu.au/activities/balloon_powered_car.html
but be original and creative!
Calculating Car’s Average Speed:
Time on 1-Meter Track
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Average Speed: _________
Balloon-Powered Car Rubric
Category
Excellent
16-20
Average
11-15
Poor
≤10
I. Design
a. Car is well-constructed and is
sturdy (not falling apart)
b. Car is aesthetically pleasing.
c. Car design shows creativity in the
utilization of resources and originality.
II. Performance
a. Car completed the 1-m track.
b. Car traveled in a straight-line
course.
III. Calculations:
Car‟s average speed has been
calculated with five trials done.
TOTAL
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Designing a Submersible
Materials:
A pair each of three
different-sized vials (S, M,
L) with lids
Beads of different sizes
Sand
Rubber band/s
Big bowl of water
Goal:
Design a submersible comprised of vials filled with either beads or sand that
will…
a. sink when first completed.
b. float mid-way when one or two vials is removed.
c. float at the surface when one or two vials is removed.
Assemble the submersible so with the least amount of points.
Point allocations:
Small Vial
1 pt
Medium-sized vial
2 pts
Large vial
3 pts
Guidelines:
You may use any number and any combination of small, medium,
and large vials.
You may use sand or beads to fill up any vial. Sand and beads
cannot be mixed together.
Vial may be filled completely or half-way or filled with any amount
of sand or beads.
Only 2 pieces of rubber bands are allowed. Only rubber bands can
be used to put the different vials together to make a submersible.
Additional challenge:
Submersible- with magnet attachedmust be able to pick up object, and
float it into the surface.
Different sized cups
contain different
objects. Objects have
magnets attached to
them.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Building a Cartesian Diver
INTRODUCTION:
What do an ice cube and a block of wood have in common?
Throw either material into water, and it will float. Well, mostly; each
object will have its bottom part immersed, but the upper
part will ride high and dry. People often say that wood and
ice float because they are "lighter than water", but this of
course is nonsense unless we compare the masses of equal
volumes of the substances. In other words, we need to
compare the masses-per-unit-volume, meaning the
densities, of each material with that of water. So we would
more properly say that objects capable of floating in water
must have densities smaller than that of water.
In this experiment, we will manipulate the density of an air pocket inside the cap
of a pen to cause it to float or sink.
Tools & Materials
•
A plastic fizzy-drink bottle
•
A pen lid with no holes in the top (if it has a hole, plug it with a little clay).
•
Waterproof modeling clay (Plasticine)
•
Water
•
A bowl or bucket
PROCEDURE:
1.
Half fill the bowl with water.
2.
Roll some clay into a ball the size of a marble.
3.
Stick the clay to the pointed end of the pen lid.
4.
Gently lower the „diver‟ into the bowl of water so that the lid remains full of
air.
5.
If the diver sinks, remove some clay. If it floats, add some more clay. Adjust
the amount of clay until the top of the pen lid only just sticks out of the water.
The experiment will not work unless the amount of clay is just right.
6.
Fill the plastic bottle to the brim.
7.
Gently lower the diver into the bottle.
8.
Screw on the lid.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Find out what adjustments need to be made if the bottle is filled up with salt water
instead of distilled water.
This experiment is all about DENSITY. When you squeeze the bottle, the air bubble
in the pen cap compresses (gets smaller) and that makes it more dense than the
water around it. When this happens, the pen sinks. When you stop squeezing, the
bubble gets bigger again, the water is forced out of the cap, and the pen cap rises.
Questions:
1. Why would a cap with a hole not work for this project?
2. What is the bob of clay for?
3. Why is it important to use a plastic bottle that is flexible?
4. What is the effect of using salt water instead of pure water?
5. Predict the effect if alcohol (a liquid that is less dense) is used instead of pure
water. What kind of adjustments would be needed for the diver to work?
Adapted from: http://www.sciencebob.com/experiments/cartesian.php
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Feeling groovy? Build a Lava Lamp!
Lava lamps are interesting and cool. Have you ever
wanted to make your own lava lamp? Lava lamps that
you buy use high heat and toxic chemicals, but you can
make a lava lamp at home using safe kitchen
ingredients.
How does a lava lamp work? Lava lamps use the
chemical properties of the liquids inside to create the
floating and sinking effects that you see.
This just proves how knowledge of chemistry can produce
something so groovy!
Materials:
Here’s how to create it:
What’s happening?
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Benzoic Acid Snow Globe
INTRODUCTION:
It's fun and easy to make your own snow globe using water and 'snow' made from
glitter or crushed egg shells, but you can use chemistry to make crystal snow that
looks a lot more like the real thing. In this project you will take advantage of the
physical and chemical properties of the compound benzoic acid to make „snow.‟ The
benzoic acid forms crystals in water that precipitates at room temperature. The
advantage of using benzoic acid is that it is non-melting at room temperature. Prepare
to have some fun!
MATERIALS:
Baby food jars with lids
Graduated cylinder
Glue gun with sticks
Electrical Tape or Duct
tape
Benzoic Acid*
Water
Hot plate or microwave
Stirring rod or spoon
Small plastic toy
Forceps or tweezers
*Benzoic acid from www.sciencekit.com is $16.50 for a
500 g bottle (Item # WW94456M06)
PROCEDURE:
1.
2.
3.
4.
Wear goggles. In a 250 ml flask or beaker, stir 1 g benzoic acid into 75 ml of
water.
Heat the solution to dissolve the benzoic acid. There is no need to boil the
water. (Alternatively, a microwave can be used to heat 75 ml of water .Dissolve
the benzoic acid in the hot water)).
Place a bead of hot glue on the inside of the jar lid. Use tweezers or forceps to
position the small toy in the glue.
While the glue is cooling, observe the benzoic acid solution. As it approaches
room temperature, the benzoic acid will precipitate out of solution to form
"snow". The rate of cooling affects the 'snow'. Slow cooling produces fine
Created for the GREAT science teachers of TRUSD by G. Myers 2010
5.
6.
7.
8.
crystals. Quick cooling produces something more like snowballs than
snowflakes.
Pour the room-temperature benzoic acid solution into the glass jar.
Fill the jar as full as possible with water. Air pockets will cause the benzoic acid
to form clumps.
Put the lid on the jar. If desired, seal the jar with hot glue or electrical tape.
Gently shake the jar to see the pretty snow!
The CHEMISTRY behind the PROJECT:
Benzoic acid doesn't readily dissolve in room temperature water, but if you heat
the water the solubility of the molecule is increased (similar to dissolving sugar in
water to make rock candy). Cooling the solution causes the benzoic acid to
precipitate back into solid form. Slow cooling of the solution allows the benzoic
acid to form prettier, more snow-like flakes than if you had simply mixed benzoic
acid powder with water. The cooling rate of water into ice affects how real snow
appears, too.
QUESTIONS:
1. Why is it important to use hot water initially?
2. Why should one not refrigerate the benzoic acid solution for faster cooling?
3. Why can‟t one use sugar or salt instead in this project?
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Engineering Project: Build a Mousetrap Car
Introduction:
In this project, you will design a mousetrap car that uses the
potential energy of a wound-up string that is attached to a mousetrap.
Although other materials may be used, the principle behind the car’s
movement remains the same.
You will get frustrated with the car as you embark on this project
along the way- but this is the way the engineering process operates!
Persevere…the end result is worth the sweat and tears! 
Objectives:
Students should be able to...
a) Design a mousetrap car that will travel a maximum DISPLACEMENT and
b) Demonstrate an understanding of the physics principles incorporated in
your design (in a report).
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Supplies:
A mouse trap
4 eye hooks
6 balloons
2 BIC pens (the smooth kind)
2 tops from pop cans (for the
serious perhaps washers, or
otherwise any other
bendable metal)
some strong string (not
pictured)
4 CDs/DVDs
Procedure
1. Strip the pens
Pull the front and back out of
the pens, making them
hollow plastic cylinders.
2. Cut and apply two
balloons.
Cut the top and bottom off
on two of the balloons.
Stretch them over two of the
CDs, which will later be the
back wheels. This will help
traction a great deal as CDs
are otherwise pretty slippery.
3. Check eye hooks.
Assure yourself that the eye
hooks fit over the pens. They
need to be loose enough to
rotate easily, but not so loose
that they rattle too much. If
not, bend them slightly so
that they do. Mine were a bit
small and needed to be
bent out a bit.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
4. Make a hole
Make a hole roughly in the
center of one of the pens. I
did this simply by screwing
one of the eye hooks in and
then removing it. It needs to
be large enough to take the
string.
5. Thread the pen
Push the string into the pen
and get it out one of the
sides. When the string is
through the pen, tie
something to the other end.
(a small piece of a toothpick
will work). Pull it back through
and make sure the
knot/object stops against the
other side of the hole.
6. Put eye holes in trap.
Screw the four eyelets into
the mouse trap along the
short sides. Try to get them to
be roughly the same depth
so that the axle that will later
go through them is
somewhat straight. Also, take
care to not crack the trap
too much.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
7. Brace
Insert the front axle (the pen
without the string) pushing it
through both pop tabs.
Pinch them to the pen so
that they won't move too
much and keep the pen
from moving sideways. Bend
them away from the eyelets
enough so that they can spin
freely against it and give
them some leeway from it
(not snugly pressed against
it). Make sure it can rotate.
8. Front wheels
Wrap a balloon around the
pen you just put in, trying to
fold it so that it's somewhat
wedge-like toward the edge
of the pen. Gently rotate
one of the CDs without
balloons on them onto it in
the same direction you
wrapped the balloon,
wedging it on the pen.
Attempt to get it to point
fairly straight and not wobbly
in relation to the trap.
Repeat for the other end of
the pen.
Created for the GREAT science teachers of TRUSD by G. Myers 2010
9. Rear axle
Push the pen with the string
into the back eyelets. Pull the
string through the eyelets so
that it's between them (or
slide through the gap if you
had to widen them). Tie the
string to the tip of the flap
that will move as the trap
springs. Those more
ambitious might want to
brace it with something
between the spring and the
back to make sure it doesn't
snag or fray, but I didn't
bother, which does mean
the string gets tangled or
frays every so often.
10. Back wheels
Attach the back wheels in
the same way the front
wheels were done.
From: DIY Network Instructables
Created for the GREAT science teachers of TRUSD by G. Myers 2010
Guide Questions:
a. In three trials, how many meters did your car travel?
__________
b. Did your car travel straight? ____________. If not, why do you think
so? _____________________________________________________
________________________________________________________
____________. What fixes could be done to make the car travel
straight? _________________________________________________
_________________________________________________________
_________________________________________________________.
c. How can you re-design your car to make it travel faster? Identify
three ideas:
1. __________________________________________________
__________________________________________________
2. __________________________________________________
__________________________________________________
3. __________________________________________________
__________________________________________________
Extension/s:
The basic design of a mousetrap is shown below:
You may investigate using other materials to make a more efficient car.
Created for the GREAT science teachers of TRUSD by G. Myers 2010