sample projects in physical science - twin · pdf file2011-2012 curriculum and instruction...

2011-2012

Curriculum and Instruction Division Science, PE, and Health Department

Sample Projects in Physical Science

Created for the GREAT science teachers of TRUSD by G. Myers 2010

Sample Projects Physical Science Grade 8

Unit Topic Sample Project Standards

Unit 1 Motion Mousetrap Catapult 2a, 2b, 2c, 2d, 2e, 2f

Paper Roller Coasters 2a, 2b, 2c, 2d, 2e, 2f

Unit 2 Forces, Part A Balloon Powered Car

Mousetrap Powered Car

2a, 2b, 2c, 2d, 2e, 2f

Unit 2 Forces, Part B Designing a Submersible

Building a Cartesian Diver 8a, 8c, 8d

Unit 3 Astronomy Model of an Asteroid (Edible) 4e

Solar System Mobile 4e

Unit 4-5 Properties, Physical Changes in Matter

Constructing a Lava Lamp

Snow Globe 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.


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?


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 soil-

like 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


Project: A Solar System Mobile

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.

In this project, you will create a mobile of the solar system, including the mi

http://www.enchantedlearning.com/crafts/astronomy/

http://www.enchantedlearning.com/subjects/astronomy/asteroids/


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.


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?

http://www.enchantedlearning.com/crafts/astronomy/solarsystemmodel/


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


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


Name: ______________________

Period No. ____ Date: __________


DATA TABLE:

Spoon Length

[ _______ cm]

Arm Length

[_______ cm]

Arm Length

[_______ cm]

Trial 1 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?


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.


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.


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

http://www.usoe.k12.ut.us/curr/Science/sciber00/8th/machines/sciber/cat.htm


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.


PROCEDURE:

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).

Two inches across = total

width

Width of track is one inch and

each folded flap is 0.5 inch


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

http://www.learner.org/interactives/parkphysics/coaster.html


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.


Appendix A Roller Coaster Sample Picture

Picture from www.paperrollercoasters.com

Students from Norwood JHS working on their roller coaster project…

http://www.paperrollercoasters.com/


Appendix B Roller Coaster Rubric

Excellent

(21-25)

Average

(16-20)

Poor

(11-15) 1. Construction and Adherence to Guidelines

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:


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.


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

http://sciencesquad.questacon.edu.au/activities/balloon_powered_car.html


Designing a Submersible

Materials:

A pair each of three

different-sized vials (S, M,

L) with lids

Sand Beads of different sizes

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 Medium-sized vial Large vial

1 pt 2 pts 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:

Different sized cups contain different

objects. Objects have magnets attached to

them.

Submersible- with magnet attached- must be able to pick up object, and

float it into the surface.


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.


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

http://www.sciencebob.com/experiments/cartesian.php


Feeling groovy? Build a Lava Lamp!

Materials:

Here’s how to create it:

What’s happening?

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!


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 Benzoic Acid* Water

Graduated cylinder Hot plate or microwave Stirring rod or spoon

Glue gun with sticks Small plastic toy Forceps or tweezers

Electrical Tape or Duct tape

*Benzoic acid from www.sciencekit.com is $16.50 for a 500 g bottle (Item # WW94456M06)

PROCEDURE:

1. Wear goggles. In a 250 ml flask or beaker, stir 1 g benzoic acid into 75 ml of water.

2. 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)).

3. 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.

4. 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

http://www.sciencekit.com/


crystals. Quick cooling produces something more like snowballs than snowflakes.

5. Pour the room-temperature benzoic acid solution into the glass jar. 6. Fill the jar as full as possible with water. Air pockets will cause the benzoic acid

to form clumps. 7. Put the lid on the jar. If desired, seal the jar with hot glue or electrical tape. 8. 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?


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).


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.

http://www.instructables.com/id/Mouse-Trap-car/step3/Cut-and-apply-two-balloons/


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.


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.

http://www.instructables.com/id/Mouse-Trap-car/step9/Front-wheels/

http://www.instructables.com/id/Mouse-Trap-car/step9/Front-wheels/


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

http://www.instructables.com/id/Mouse-Trap-car/step10/Rear-axle/

http://www.instructables.com/id/Mouse-Trap-car/step10/Rear-axle/


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.

sample projects in physical science - twin · pdf file2011-2012 curriculum and instruction...

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