Mousetrap Vehicle Physics – Science 10

Mr. James

Table of Contents1

Day Activity

1 Explain Project, Research

2 Finish Research

3 Design Vehicle

4 Build

5 Build

6 Build

7 Test

8 Test

9 Distance and Displacement

10 Potential Energy

11 Kinetic Energy

12 Work

13 Speed and Velocity

14 Acceleration

15 Analysis

16 Analysis

17 Review

18 Review

19 Unit Test

20 Race Day!

Mousetrap Vehicles – Day 1

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Guiding Question:

How can a mousetrap vehicle help us better understand the physics at work in the world around us?

Introduction:

Your task is to build an originally designed vehicle powered by a mousetrap to run along a course, which will be five meters long (minimum). Your vehicle will be designed to compete in one of three categories below. Each category requires specific parts of the build to be customized, so be sure you start your build with the end goal in mind. A very popular method of propulsion is to tie one end of a string to the arm (or an extended lever arm) on the mousetrap and the other end to the axle. By winding the string around the axle, the mousetrap's spring, when released, pulls on the string causing the wheels to turn and thus making the vehicle move (however, other creative ways to convey power from the mousetrap to the vehicle can be used).

There will be team entries in the following events:

★ SPEED: Fastest vehicle to finish wins. To be run in heats of three vehicles.

★ DISTANCE: This is the most popular and the easiest to judge. The vehicle that travels the longest linear distance on one swing of the mousetrap lever wins.

★ MOST POWERFUL: The vehicle must be able to pull a small trailer loaded with weights. The vehicle moving the greatest weight for a designated distance is the win.

Key Concepts:

a) Design a mousetrap vehicle that will travel a maximum speed/acceleration over a 5 meter race. b) Demonstrate an understanding of the physics principles incorporated in your design (in a report). The project consists of 5 phases: Mousetrap Vehicle Design Procurement of parts - Pass CHECKPOINT 1 Mousetrap Vehicle Construction - Pass CHECKPOINT 2 Mousetrap Vehicle Performance Evaluation - Race day. Mousetrap Vehicle Physics Analysis (Report)

Research - Day 2

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As with any good project, you must first research to develop necessary background information before you get started. Use the following websites to answer questions 1-5 below:Note: Of course you may use other sites you find, if they are relevant to your research.

http://www.docfizzix.com/topics/science-concepts/MouseTrap-Vehicles/

http://www.docfizzix.com/topics/construction-tips/Mouse-Trap-Vehicles/adjusting- pulling-- force.shtml

http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap- racers-friction.shtml

http://www.drivingscience.org/mousetrap-vehicle-resources.html

http://www.real-world-physics-problems.com/mousetrap-vehicle-physics.html

Questions:

1.  What are the forces applied to the mousetrap car that help it to move forward?________________________________________________________________________________________________________________________________________________

2. What forces acting on the mousetrap vehicle are slowing it down or decreasing its momentum?  Be specific.________________________________________________________________________________________________________________________________________________

3. What can you do to decrease the forces that are slowing your vehicle down?________________________________________________________________________________________________________________________________________________

4.  Draw and label the parts of any example of a mousetrap vehicle below:  Wheels, drive axle, lever arm, chassis (body), mousetrap

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5.  List at least two items that could be used for each of the following parts. Do you have these items at home? Or would you have to purchase them? Are they expensive? Check it out!

a. Wheels: ___________________________________________________________

b. Axle: _____________________________________________________________

c. Body: _____________________________________________________________

6.    http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-propulsion.shtml

a. In the most basic terms, how would you explain how a mousetrap vehicle works using the terms potential energy, kinetic energy, friction and momentum?  ______________________________________________________________________

b. What is one way you can connect the string to the axle? Is there more than one way?______________________________________________________________________

7.    http://www.docfizzix.com/topics/construction-tips/Mouse-Trap-Vehicles/adjusting-pulling-force.shtml

a. If you are building your car for speed, where should you place the mousetrap on the vehicle?______________________________________________________________________

b. If you are building your car for distance, where should you place the mousetrap on the vehicle?______________________________________________________________________

8.  http://www.docfizzix.com/topics/construction-tips/Mouse-Trap-Vehicles/adjusting-pulling-force.shtml

a.  If you want to build your vehicle for speed/power, how long should you make your vehicle’s lever arm for best performance?______________________________________________________________________

b. If you want to build your vehicle for distance, how long should you make your vehicle’s lever arm for best performance??______________________________________________________________________

9. When you test your vehicle, if your vehicle stops or slows down, what are some possible causes of this and what should you do to fix it?

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http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-racers-friction.shtml

________________________________________________________________________________________________________________________________________________

10.  If your axle slides back and forth, the wheels to rub against the chassis which slows/stops the vehicle. What can be done to fix this?http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-racers-friction.shtml______________________________________________________________________

11.  List four (4) ways to help your vehicle travel a longer distance.http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-distance-basics.shtml

1.____________________________________________________________________

2.____________________________________________________________________

3.____________________________________________________________________

4. ___________________________________________________________________

12.  When designing a mousetrap vehicle, what are two variables that ultimately determine performance?  How can you minimize the one that slows you down?http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-distance-basics.shtml

The two variable are: _______________________________________________________

How do you minimize one: ________________________________________________________________________ 13.  Designing your car for speed requires different physics than if you design your car for distance. List four (4) of these differences below.http://www.docfizzix.com/topics/records/Mouse-Trap-Vehicles/

a. ________________________________________________________________________________________________________________________________

b. ________________________________________________________________________________________________________________________________

c. ________________________________________________________________________________________________________________________________

d. ________________________________________________________________________________________________________________________________

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14.  Restate each of Newton’s Laws of Motion and then explain how the law would apply to mousetrap powered vehicles.http://www.docfizzix.com/topics/science-concepts/MouseTrap-Vehicles/newtons-laws.shtml

Law One: __________________________________________________________________________________________________________________________________________________

How does it apply?__________________________________________________________________________________________________________________________________________

Law Two:__________________________________________________________________________________________________________________________________________

How does it apply?__________________________________________________________________________________________________________________________________________

15.  List three (3) considerations to design a mousetrap vehicle for distance.http://www.docfizzix.com/topics/design-basics/MouseTrap-Vehicles/mousetrap-distance-basics.shtml

a. ________________________________________________________________

b. ________________________________________________________________

c. ________________________________________________________________

HINT: Go to page 24/25 and complete the analysis questions 1-5 while this stuff is fresh in your mind! Keep the answers to the questions, so you can include them in your report at the end.

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Mousetrap Vehicle Planning Sheet – Day 3

Make 2 small sketches of possible designs for your mousetrap vehicle.  Include how many wheels you will use and label what you will use for each part of the mousetrap vehicle (see Question #4 if you need to remember the parts).

You will need to:

1. Draw the vehicle using a top view/side view. 2. Label all parts of the vehicle including materials used for each part3. Include measurements (to scale if you are able)

INITIAL DESIGN

Approved By Mr James: __________________________Calculating Distance and Displacement – Day 9

Questions:

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1. Define the term distance ______________________________________________________________________________________________________________________________________

2. Define the term displacement ______________________________________________________________________________________________________________________________________

3. What is the difference between the two terms?______________________________________________________________________________________________________________________________________

4. The shortest distance between two points is found using a ______________ line. This is an example of ___________________. In this activity you are going to find the displacement and distance your vehicle travels in order to determine if you need to make any changes to the alignment of your wheels.

Procedure:

Use the diagram below to help answer the following questions:Diagram/Calculations for Displacement and Distance

5m

1. Set out a piece of string (AB) 5 meters long. Make sure this string is straight and put a piece of tape at both ends to hold it in place.

B

A CAB = 5m

BC = _________

Formula/Calculations for AC;

AC = _________

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2. Take a second piece of string (BC) and tape it at one end (B), but do not string it out. This is the point where your vehicle will start.

3. Place your vehicle down at point B.4. Run your vehicle. Did it follow the straight string? If not, string the second piece of

string in the direction your vehicle was travelling.5. Measure the distance your vehicle travelled using a ruler/meter stick.6. Now using Pythagorean Theorem, determine the length of line AC to find out how

much extra your vehicle has travelled compared to the displacement.

Conclusion:

1. What was the displacement your vehicle should have travelled if it went straight? (Remember to include direction if this is a vector quantity)

______________________________________________________________________________________________________________________________________________

2. What was the distance your vehicle ACTUALLY travelled?______________________________________________________________________________________________________________________________________________

3. How much extra distance did your vehicle travel compared to the shortest displacement it could have travelled.

______________________________________________________________________________________________________________________________________________

4. Is this an acceptable? Are you going to make any changes to your vehicle in order to decrease the distance it travels in the wrong direction? If, so describe the changes below, so you will remember to put them in your analysis at the end!

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Extra Practice Questions (Will be marked /5 )

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1. What is the difference between scalar and vector quantities? Give two examples of each in your answer.

Calculate the distance and displacement in each of the following situations. Draw diagrams if you need to.

2. David walks 3 km North, and then turns East and walks 4 km.

3. Amy runs 2 miles South, then turns around and runs 3 miles North.

4. Derrick crawls 4 feet South, and then turns East and crawls 6 feet.

Measuring Potential Energy – Day 10

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We now know how much kinetic energy we got from our mousetrap vehicle. But to work out the efficiency we need to know how much stored energy was available in the mousetrap.

The Energy stored in a spring can be found by the following equation:

E potential = potential energy stored in the spring (Joules)

F = the force the spring produces in Newtons (N)d = the distance over which the force acts in metres (m)

To do this we need to know how much Force the arm on the mousetrap produces.

Potential Energy Experiment Results

6) Use the Newton Gauge to measure the Force produced by the spring. You may find that the Force is not the same as you pull the spring back from the start to the full extension. Record your results in the space below.

Fill out the table to record the Force recorded at various angles:

Angle (°) Force (N)

Average Force Applied:

Now that we know the average force that is applied we need to determine over what distance that force acts. This can be found by calculated how far the end of the mousetrap “hammer” moves. The end of the hammer traces out part of a circle. The radius of the circle is equal to the length of the hammer.

7) Calculate the distance travelled using the equation for the circumference of a circle.

8) The energy stored in the spring is equal to the Average Force multiplied by the Distance over which the force acts. Calculate the energy available from your vehicle and record it in the space below.

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9) The efficiency of your mousetrap vehicle is given by the Kinetic Energy divided by the Potential Energy multiplied by 100. Calculate the efficiency of your mousetrap vehicle and record it in the space below.

Extra Practice Questions (Will be marked /5 )

1. An engine is filled with gasoline that contains chemical energy, and when the engine is started, it begins transforming that chemical energy into mechanical energy. Over the course of a few seconds, the engine transforms 7,000J of chemical energy, but 5,000J of that energy is ‘wasted’ in the form of thermal energy.

a. How much energy does the engine transform into useful mechanical energy during these few seconds?

b. Calculate the efficiency of this engine

2. A fan is capable of using 4800J of electrical energy each minute, converting 4000J of it into kinetic energy of the fan. What is the efficiency of this fan?

Measuring Kinetic Energy – Day 11

Kinetic Energy (KE) is the energy of motion, which may be horizontal, vertical, or spinning motion. To calculate the KE of a moving object, use the following formula:

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Example:

Questions (Be sure to include formula and show work):

1. A Wooden mousetrap vehicle weighs 500g and is moving at a speed of 2m/s. Calculate the kinetic energy (in Joules) of the vehicle.

2. A ping pong ball has a mass of about 2.45 grams. Suppose that Forrest Gump hits the ball across the table with a speed of about 4.00m/s. What is the ball’s KE?

3. Determine the kinetic energy of a 625Kg rollercoaster moving with a constant speed of 18.3 m/s.

4. Determine the kinetic energy of YOUR mousetrap vehicle.

a. Mass of your vehicle – _____________b. Speed of your vehicle m/s (Use your average speed from Day 10) _____________c. Calculations:

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d. Final Answer:

Extra Practice Questions (Will be marked /5 )

1. A curling rock with a mass of 20.0 kg slides down a sheet of ice at a speed of6.00 m/s. What is the kinetic energy of the curling rock?

2. A 200-g Nerf dart is shot from a dart gun with a kinetic energy of 3.60 J. What was the initial speed of the dart?

Measuring Work – Day 12

The work done on the mousetrap arm is found using the formula W = F d, where F is the force (in Newtons) applied to the mousetrap vehicle spring arm and d is the distance (in m) through which the force is applied.

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In order to find the force (Newtons) applied to your lever arm, you need to use a spring scale and calculate how much force it take to pull your lever arm to the “ready” position. You may find the force is NOT the same through the entire range of motion, so check the force in several places. Be sure to use simple degrees as your increments (23.5°, 45°, 68.5°, 90° etc)

Angle (°) Force (N)

Average Force Applied:

To find the distance you pulled back you have to use the length of the mousetrap arm.

Write the length of the mousetrap arm here: ___________.

We need to find out what part of the circumference of a circle the force was applied to the mousetrap arm. The maximum would be half a circle (180°) if the mousetrap started at one end and completely unwound to the other end.

If it didn’t (and probably it didn’t go through the entire 180°), we need to find out how much it did go through.

STEP 1: Find out the circumference of the circle the mousetrap arm would make if it made an entire rotation. C = 2r = ________________ m

STEP 2: Divide your circumference by 2: C 2 = ________________ mSTEP 3: Now if it didn’t go through the entire half circle, estimate how much of the half-

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circle the arm goes through before it stops. Choose one of the following percentages: 10% 20% 30% 40% 50% 60% 70% 80% 90%

STEP 4: Now multiply your half-circumference value by the decimal equivalent of the percentage. EX: If your mousetrap vehicle arm went through 20% of the half circle (see picture at right), then your final distance, d, will be C2 0.20

Write your distance here: d = ____________ mSTEP 5: Now find the work done by you to move the mousetrap arm into position.

W = F d = _______________ Joules (the unit of work and energy)

Extra Practice Questions (Will be marked /5 )

1. While bench pressing, you lift a barbell that weighs 345 N a distance of 35 cm (must be in meters!). How much work do you do on the barbell!? (1.2 x 102 J)

2. Gravity exerts a force of 650.0 N on a skydiver over a distance of 3580 m. How much work does gravity do on the skydiver? (2.327 x 106J)

3. A crane does 4 114 J of work while lifting a 1 766 N statue onto a pedestal. How high does the crane lift the statue? (2.330m)

Measuring Speed and Velocity - Day 13/14

Today, we will be determining the speed of your vehicle! Think about driving in your vehicle. How do we calculate speed? Speed is calculated in Km/h of course. To determine the speed or velocity of your vehicle, we need to understand a view terms.

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Speed – the distance travelled by your vehicle during a given time interval divided by the time interval.Velocity – the displacement of your vehicle during a time interval divided by the time interval. NOTE: Direction will be the same in both cases.

TASK: Read Pages 182 and 183 in your textbook to help you understand the difference between speed and velocity.

Procedure: 1. Take a piece of string 5m long and tape it to the floor at each end.2. Use a meter stick to mark out 1m increments along the string.3. Open the “timer” on your phone.4. Have one person stand directly over the first meter mark, so they can see when the wheels pass

that point. The timer should move with the vehicle as it goes along.5. Have one person start the vehicle at the beginning point with the front wheels touching the start

line.6. Run your vehicle. When the front wheels touch the 1m mark, hit “Lap” button. 7. Move along with your vehicle, so your eyes are above the front wheels and you can see the front

wheels pass over the tape. When the wheels reach the 2m mark hit the “Lap” button. (These will be your interval times t1, t2, t3, etc.)

Test your vehicle a minimum of 3 times in the hall. Record the distance traveled at each time interval for each trial. Interval Times

Trial # t1 t2 t3 t4 Total (s)18

12345AVG:

Speed (Use your total time from the previous graph to complete this chart)

Trial # Time (Seconds) Distance (meters) Speed (s = d/t)12345AVG:

Velocity (See your above time trials for more information)

Trial # Time (Seconds) Distance (meters) Velocity (v = d/t)12345AVG:

1. What is average speed of your vehicle over the 5 meter displacement?

2. What category did you build your vehicle to compete in? _________________a. How does the speed of your vehicle fit with your choice of category? For example, if your

vehicle travels a speed of 0.46m/s, is that a better fit for the speed or distance category?

3. Speak to three other groups and write down the speed of their vehicle was over the same displacement (5m).

a. ____________________

b. ____________________

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c. ____________________

4. How does the speed/velocity of your vehicle compare with the other groups?

5. What changes do you need to make to your vehicle to be more competitive?

Graph the results in the table below. Make sure to label each trial in a different color. Include a legend!

X-Axis (horizontal): Time – (seconds) Y-Axis (vertical): Position (meters)

________________________________________________

Analysis:

1. Was the speed/velocity constant for each of the trials? How do you know? (Hint: Calculate the Slope)

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2. How can you determine if it was? (Hint: Calculate the Slope)

3. If the velocity was constant, what would it look like on a graph? Use graph A, B and C to show positive uniform velocity, negative uniform velocity and non-uniform velocity respectively.

1. How far was your vehicle being pulled by the string? From the graph, is it possible to determine when the string was no longer pulling your vehicle? Explain using a reference to the time and angle of your graph.

_____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

2. What was your vehicles maximum speed over the timing distance? When did this occur? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

3. Discuss your findings with two other groups. What was the speed/velocity of their vehicle? Based on these discussions, are there any changes you are going to make to your mousetrap vehicle? Note the changes below.

____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

A B C

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Extra Practice Questions (Will be marked /5 )

That was enough practice calculations for one day don’t you think? No practice questions for this day. If you would like to find your own and do some for extra practice, you may do so! Hand them in for some bonus marks! One per question up to a maximum of three (3) marks! Complete the in them space below.

Measuring Acceleration – Day 15

Acceleration – any change to the velocity of an object during the time interval. The change can be positive (increase) or negative (decrease). Since velocity is a vector quantity, then acceleration is a vector quantity.

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NOTE: S2 means that the velocity is changing by x meters/second every second

EXAMPLE:

1. A drag vehicle reached a speed of 145.08 m/s in 4.48s. What was the dragsters average acceleration? Assume it is in the positive direction.

For this day, we do not need any new calculations. All we have to do is take the velocity (which you found in on Day 13/14 – Speed and Velocity) and substitute it into the formula above.

Procedure:

1. Using trial number one from speed and velocity, input the velocity of your vehicleinto this formula to find acceleration for trial 1 below.

2. Using trial number one from speed and velocity, input the velocity of your vehicle.into this formula to find acceleration for trial 2 below.

Trial Number Time (Seconds) Δt Δv Acceleration12345AVG:

Mousetrap Vehicle Physics Analysis Report – Day 16/17/18

Answer the following questions completely (include formulas and/or calculations where appropriate). Your answers may be written or typed and a minimum of 300 words.

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Types of Energy: (Introduction/Background)

1. Energy exists in a variety of forms – List nine examples of the various forms of potential and kinetic energy. Place a (P) if it is potential energy and (K) for kinetic.

2. Describe how potential energy was transformed to kinetic energy in your mousetrap vehicle.

3. Explain that in the absence of resistive forces, motion at a constant speed requires no energy.

Thermodynamics and Motion:

4. Using Newton’s first two (2) Laws of Motion, explain the energy conversions that were occurring in your vehicle.

5. Using the 1st and 2nd Laws of Thermodynamics, explain why combustion engines are not 100% efficient? (Hint: Think of thermal energy)

Design/Materials: (Procedure/Body Paragraphs)

6. What factors did you take into account to decide the number of wheels you chose in your design?

7. What kind of wheels did you use on each axle? What is the effect of using large or small wheels?

8. Discuss the effect of the length of the lever arm in the pulling force of your vehicle. 9. How is the balance of a wheel, around its center, related to the vehicle’s

performance? 10.How does the distribution of weight of the vehicle affect the traction of the wheels? 11.How does the placement of the mousetrap affect the performance of your vehicle?12.What are the two types of friction that affect the performance of your vehicle? 13.What problems related to friction did you encounter and how did you solve them? 14.Discuss the major problems encountered in the performance of your vehicle and

what did you do to solve them.15.Explain how the process of design and redesign led you to the current model of your

vehicle? How does this idea apply to science?

Calculations: (Be sure to explain each formula and how to complete the calculations for it.

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Include pictures/diagrams with your explanations if necessary)

16.Explain the difference between distance and displacement. Be sure to use the terms vector quantity and scalar quantity in your explanation.

17.How did you calculate the potential energy of your vehicle?18.How did you calculate the potential energy of your vehicle? It is Important to note,

this calculation was in the absence of resistive forces! Explain what that means in your explanation?

19.How did you calculate the work done by your vehicle?20.How is displacement used in the calculation of velocity? How is this different from

the calculation of speed?21.How did the speed of your vehicle compare to other groups?22.How did you find the acceleration of your vehicle?

Conclusion:

23.Comment on the efficiency of your mousetrap vehicle. (Useful vs wasted energy)24. If energy cannot be lost in the conversion, where did your energy go? Why is your

output not equal to the input?25.List the modifications you have made throughout your build and why you made

them. What were you trying to overcome with the change?

Extension (Optional):

Can you produce graphs of the vehicles position, velocity and acceleration against time. (Three graphs) Can you explain the shape of these graphs?

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