Learning Objectives

• To develop an understanding for the holistic design process.
• Develop a solution to solve a real life problem.
• Sketching ideas.
• Develop researching skills using the internet.
• Develop an understanding of the properties of basic engineering forces (Energy, Forces, Motion).

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Important: This is an introductory unit to the design process, but also you will notice that you are onboarding students to projects where supplies are not provided until they complete plans, goals, and sketches.

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General Summary Of Unit:

Students will develop an understanding for the holistic design process, they will develop a solution to solve a real life problem. Students will sketch ideas, research various mousetrap ideas and develop an understanding of basic engineering principles such as Energy, Forces, Motion.

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Skills students need or will develop:

• An understanding of simple machines
• Continue to improve on the concept of Iteration of the design process when solving problems or building things.

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Student Facing Slides Chunked into Sections

• Mousetrap Cars Part 1
• Mousetrap Cars Part 2
• Mousetrap Cars Part 3
• Mousetrap Car Pre-Assessment
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Goals For A Final Project

Each Student will create a mousetrap car for SPEED (15 Foot Race) OR DISTANCE, using one standard 5 x 10 cm mousetrap, the exact same mousetrap that is supplied to the entire class. The trap must remain intact; the spring cannot be modified or moved from the base of the mouse trap. Screws and nails, zip ties for example - can be used to attach the mousetrap to the car chassis, but wood cannot be cut or removed from the base. No launching ramps are allowed; all parts of the vehicle must move forward as a whole. The only energy source allowed at the start of the race is that which is stored in the mousetrap spring. You may not hold the vehicle during release or push the vehicle. If a student build a successful (basic) mousetrap car, he/she may construct one using multiple traps or modifying them to increase speed or distance.

Design and care for speed or distance and excel in the iterative design process by improving it.

"TrapMotion Motors: Exploring Movement through Mousetrap Cars"

Speed Or Distance?

Intro

Teacher Notes & Resources For Lesson:

• You can keep it limited and have most of the students build the common mousetrap car design or you can open it up and have students design what they want.
• Provide the basics, but you could open it up. I would recommend keeping it simple it it is your first shot at this.

As Always, I WOULD RECOMMEND YOU BUILD A CAR ASAP - Do not share it with your students.

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*Today students will sketch a design of a simple car and label the parts with a partner.

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** ONE Key to this entire project is the String IS NOT TIED to the axle, it is wrapped around and then comes off. That is why it is important to teach students how to tie Knots & Loops.

Materials Needed:

• Get your mousetrap basic parts ordered on slide 10

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1 System Of A Mousetrap car

Lesson Starter

Have you have ever seen a mousetrap car or have any idea what it is? (Yes or No)

It its simplest terms, a mousetrap car is a small vehicle powered by a mousetrap that converts the energy stored in the spring of the mousetrap into motion.

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After watching this (2 Minutes) of this simple video, what makes some cars successful and some a failure?

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Quick Pre-Assessment - can do individually or as a class.

Objectives

• Understanding the basic principles of motion:
• Understand the basic principles of motion, such as force, velocity, and acceleration.
• Introduced to the idea that the mousetrap car works by converting potential energy (stored in the spring of the mousetrap) into kinetic energy (the motion of the car).
• Learn about the forces that affect the car's movement, such as friction, air resistance, and gravity.

Parts of the Mousetrap Car

1. Mousetrap: The mousetrap is the power source of the car. It stores energy in the spring which is released when the trap is triggered.
2. Axle: The axle is a rod that connects the wheels and allows them to spin.
3. Wheels: The wheels are what make the car move. They are attached to the axle and spin when the car is in motion.
4. Body: The body of the car is the structure that holds all the parts together. It can be made of a variety of materials, such as wood or plastic.
5. Drive mechanism: The drive mechanism is what converts the motion of the mousetrap into the motion of the wheels. It can be as simple as a string or as complex as a gear system.

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What Important Role Does Each Material Play?

Mouse Traps Bulk Pack (24 Cars)

Drinking Straws Drinking straws (100 Cars)

Washers Washers (25 Cars)

Cotton string Spool (100 Cars)

Cds - 100 pack CD (25 Cars)

Dowel Rods Rods (25 Cars)

Cable Ties Cable Ties (50 Cars)

A 4 x 8 Piece of Corrugated Sheets(16 to 20 Cars)

Balloons - (50 Cars - Drive Wheels Only)

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You will be split in teams and each team will sketch the mousetrap car above and explain in detail the importance of the part and what will happen if not used correctly. SPLIT ASSIGNMENTS - Sketcher, Researcher, Documenter.

What will be hard?

In looking at designing a mousetrap car what part do you feel is going to be the most challenging?

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How do you think Friction will impact your mousetrap car?

1. Friction: The force that opposes motion between two surfaces that are in contact with each other. Friction is caused by the microscopic roughness of the surfaces, which creates interlocking and resistance to motion.
2. Surface Area: The total area that a surface covers. The greater the surface area, the greater the amount of friction that will be produced.
3. Coefficient of Friction: The value that represents the amount of friction between two surfaces. The coefficient of friction is affected by factors such as the types of materials and the amount of force applied.
4. Static Friction: The frictional force that exists between two surfaces that are not moving relative to each other. Static friction must be overcome in order to start an object in motion.
5. Kinetic Friction: The frictional force that exists between two surfaces that are in motion relative to each other. Kinetic friction is generally lower than static friction, but still opposes the motion of the object.

2 Design Brief

Each Student will create a mousetrap car for SPEED (15 Foot Race) OR DISTANCE, using one standard 5 x 10 cm mousetrap, the exact same mousetrap that is supplied to the entire class. The trap must remain intact; the spring cannot be modified or moved from the base of the mouse trap. Screws and nails, zip ties for example - can be used to attach the mousetrap to the car chassis, but wood cannot be cut or removed from the base. No launching ramps are allowed; all parts of the vehicle must move forward as a whole. The only energy source allowed at the start of the race is that which is stored in the mousetrap spring. You may not hold the vehicle during release or push the vehicle. If a student builds a successful (basic) mousetrap car, he/she may construct one using multiple traps or modifying them to increase speed or distance.

Together As A Class

UNDERLINE KEY POINTS IN THE DESIGN BRIEF

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Day 2

(Individual) Step 1. Identify the Problem, Opportunity, or Goal: Briefly explain the problem you are going to try to solve? (10 Minutes)

(Individual) Step 2: List Criteria and Constraints for the solution (10 Minutes)

You will be split into teams and each team will research one concept assigned to them, be prepared to share out in 10 minutes. Explain how your concept relates to this challenge. Explain why we need to learn it to be successful in this challenge?(Car chassis, potential energy, traction, power source, Axle, lever arm, tying a loop, gears, friction, & weight)

Exit Ticket:

What Prior Knowledge do you have about mouse trap cars, levers, or gears?

Resources:

• How to build a Mousetrap Car
• This is a resource for kids who are stuck, I just recommend putting the link as a resource in a schoology folder
• Mark Rober Video
• Who doesn’t love Mark Rober?
• Plus it introduces Mechanical Advantage (cool enrichment idea)

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Lesson 3: Frame Design

Teacher Notes & Resources For Lesson:

• You are onboarding in the Lab - Focus on “Standards of Workmanship”
• You choice if you have students in groups or as individuals. (If someone has not passed safety exams or brought back safety contracts, they can watch, but can not build)
• Final top views should ONLY be accepted if all lines are drawn with a ruler and are measured EXACTLY.

Similar to a 6th grade all wound up car the frame has to be secured, look at the photo how there are frames on top of the car to support it.

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Assess the Design as an Exit Ticket!!!

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Materials Needed:

• Have the 6 x 9 piece of corrugated Poster Board for your frame cut out.
• Scrolls saws are great for cutting along with scissors or utility knives.
• MT Car Design

3 Frame Design

Lesson Starter

You will be provide a 6 x 9 piece of corrugated Poster Board for your frame.

Sketch out the top view of what you think the chassis will look like on a blank sheet of paper. USE THE ½” graph TEMPLATE

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ALL Dimensions must be on your sketch, an example is shown, but you are encouraged to develop a different frame design.

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* Your final top view will ONLY be accepted if all line are drawn with a ruler and are measured EXACTLY.

Objectives

• Understanding the importance of structural design:
• Understand the importance of structural design in building a mousetrap car. Students can be introduced to the idea that the frame of the car provides support for the other components and affects the car's overall stability and speed.
• Make informed decisions about how to design and construct your frame

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Select YOUR CHOICE

• Evaluate the 3 ideas you generated. It is important to select what appears to be the best idea that solves the problem. Use the decision matrix below to evaluate your 3 ideas. Rank each design based on the design factors listed below. Rank your ideas 1 being the worst and 3 being being the best

15 Minutes to research & have the top view completed.

To do your research, go to Google and type in Mousetrap cars for distance or speed, YOU PICK!!!

5 Minutes mark where your axles will cross.

You axle line must be EXACT perpendicular to the frame of your body a good tool to use in a small square.

Exit Ticket

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Hold up your Mousetrap car top view - Explain your design in 10 seconds!!

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5, 4 or 3 Points

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ONCE COMPLETED YOU WILL BE ASSIGNED TO A TEAMMATE

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Lesson 4: Wheels and Axles

Teacher Notes & Resources For Lesson:

• We are onboarding students for being an Empowered Learner all year. NO Sketch, No Research - NO Mousetrap car.
• Talk about “Standards of Workmanship” and can students handle a mousetrap, you can tell them if used improperly, you will take yours back.
• Remember no parts are handing out yet, except the frame. This is one of the first project, “dangle the carrot” it getting students to practice good standards of workmanship.

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Do not let a student attempt to do 3 wheels unless they are very confident they can attach them and have the CD stable.

• There are a few tips for attaching their CDs to the Dowel Rods, keep in mind they do not want Friction on the end of the straw. Sometimes a washer the diameter of the dowel rod can work. I have see where students wrap small strips of Duct Tape on the dowel rod to create a tight fit on the CD.

Materials Needed:

• Show the Wheels (CD’s) & Axles (Dowel Rods In Straws) - DO NOT PASS OUT!!!
• Page 2 of MT Car Design

3 - Wheels and Axles

Lesson Starter

Today we will determine our wheels and axles, but how does a car really work.

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As you watch the video answer the key questions on your planning sheet.

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3 - Wheels and Axles

Lesson Starter

How many wheels do you plan on having?

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Why do you think it is harder to make a 3 wheel vs a 4 wheel car?

With three-wheeled cars, it will be easier to adjust the steering of the vehicle because there are fewer wheels to be aligned. The advantage of using four wheels is the car stability. WHICH WILL YOU CHOOSE?

Objectives

• Understanding the importance of structural design:
• Understand the importance of structural design in building a mousetrap car. Students can be introduced to the idea that the frame of the car provides support for the other components and affects the car's overall stability and speed.
• Make informed decisions about how to design and construct your frame

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All Students will be provide 4 CD’s for their mousetrap car, but you may bring in something different if you want and it is approved by me.

Research:

Best Wheels for mousetrap cars?

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How to attach mousetrap car wheels to the axle?

Example in a 30 second search

IMPORTANT: Keep in mind without your sketch and doing research, YOU WILL NOT GET MOUSETRAP PARTS to make your car, which will be happening soon

Document how you are using your wheels and attaching them to your axles on the back of your

TOP VIEW SKETCH

Do NOT SHOW until after research and answers:

Use a large wheel with a small axle (i.e., a large wheel-to-axle ratio). A large wheel with a small axle will cover more distance per each turn of the axle when compared to a smaller wheel with the same axle. Axels can be successfully made from just about any “rod” type material. Straws, skewers, pencils (round not hex-shaped), dowels, hangers. The wheels must be securely attached to the axles. With distance vehicles, you want a small force over a long distance; therefore, use a large wheel with a small axle.

Tips in Construction

Getting Close to BUILD DAY, Make sure you are caught up on your assignments

Lesson 5- Pull String & Lever Arm

Teacher Notes & Resources For Lesson:

• The longer the arm, the less power, but the more times it is wrapped around the axel and will increase distance.
• A short arm, will have more power, but students need to be careful, it will put a tremendous amount of torque on the arm and axle and the wheels may just spin out.
• Balloons cut and wrapped around the CD’s provide traction.
• Preview the car spinning in the snow and make sure students get the concept of too much power, not enough traction, causes a spin out.

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Where the trap is located, the best place for distance is in the front of the car, KEY: when the rope is wrapped around the axle the arm of the mousetrap should be Above The AXLE. Notice the two designs below.

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Materials Needed:

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• Cut some 8” pieces of string
• If you have some various mouse traps with different length lever arms, that would be great to demo the difference between the two.

4 - Pull String and Lever Arm

Lesson Starter

In groups of 2, get one of the 8” pieces of string off of the desk and tie a 1” loop at the end of the string.

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Now Take a pen or Pencil and a knot at the other end to secure the pencil to the string.

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Lever Arm

1. Let’s do some research the longer the lever arm is, what happens to the mechanical advantage?

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2. If you want speed do you want a short or long arm? Why?

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3. If you want distance do you want a short or long arm? Why?

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Why is the car spinning and how could you get it out?

How do these solutions relate to your mousetrap car?

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• Let a Bit of Air Out of Your Tires
• Add Weight
• Add Traction with Sand, Kitty Litter or Cardboard
• Apply Less Power

From the previous discussion on the length of the arm and with the solutions above, what would cause your mousetrap racer to spin out and what could you do.

Answer: A Longer Arm, Add traction to your wheels using balloons around your CD, Add Weight over the power wheels, Add wider tires to create more friction to the road surface.

Exit Ticket: Deciding where to put your mouse trap and the length of your arm (Get Your TOP View Back Out)

Teacher Example

6 Inches For This Design

Key Points with Pull String and Lever Arm

Pulling String

String is often used to transfer a force from one point to another. Choosing the proper string is critical. If you use a string that cannot handle the pulling force, it will snap as you release the mouse trap. If you use a string that is too thick, it will not wind around the drive axle smoothly, causing the pulling force to be inconsistent. DO NOT USE THREAD. The string must not be tied to the axle. If the string is tied to the axle, it will begin to rewind itself and will cause your car to come to a sudden stop. In order to achieve maximum performance from your mouse-trap car, it is important that the pulling string does not slip off the drive axle prematurely. A release hook can be constructed to allow the string to remain connected to the axle during the pulling phase and then release once the pulling has stopped.

Lever Arm

The distance from the turning axis to the point of contact is called the lever arm. By adjusting the length of the mouse trap’s lever arm, you can vary the force that is applied to the wheels of your car. Long lever arms decrease the pulling force while short arms increase the pulling force. The longer the length of the lever arm that you use, the more string you can wind around the drive axle. Therefore, a greater overall travel distance can occur as the string is pulled off the drive axle. Lever arms should not extend past the axle when in the lowered position. For correct lever arm length make sure the lever reaches the axle. If the lever end is L-shaped then it will center the string on the axle. When cutting the mouse trap hammer to add length to the lever arm be sure you remove the side (arm of the hammer) that does not attach to the long arm of the spring.

Eliminating all forms of friction is the key to success no matter what type of vehicle you are building. Minimizing surface friction on a mouse-trap car allows its wheels to spin with less resistance, resulting in a car that travels faster, farther and wastes less energy. The most common area where surface friction will occur is between the axle and the chassis. Look your car over with a scrutinizing eye in order to reduce the total amount of friction acting on your vehicle.

Lesson 6: Construction (2-3 days)

Teacher Notes & Resources For Lesson:

• It is important to have checkpoints and an assessment to keep the students on task. Access their work!!!
• Day 1
• Cutting out the Frame OF THE CAR (5 / 4 / 3) points
• Attaching the axles (5 / 4 / 3) points
• Straightening out the Mousetrap Car Arm and creating and attaching the rod, if necessary(5 / 4 / 3) points
• Gluing my mousetrap car in the proper position on my car. (5 / 4 / 3) points

(SAVE 5 minutes at the end of the period for every group to hold up their car, celebrate the successful groups) - In two days it is race day, if a group is not ready, they do not race) - You could always extend it in ELT for students, but do not hold up your class. Keep the pace moving.

• Day 2
• Measuring the String, creating a loop and connecting the string to the mousetrap rod. (5 / 4 / 3) points
• Attaching the Wheels to the Axles (5 / 4 / 3) points
• Creating a small hook to you axel and attaching it properly (5 / 4 / 3) points
• Testing your mousetrap car by just pushing it on a desk and making any necessary adjustments (5 / 4 / 3) points

Potential Lesson Timers used for pacing

Materials Needed:

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All Mousetrap Car Supplies will be needed

Tools: Hot Glue, Cutters or scroll saw for balsa wood.

5 - Construction

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List 3 Key points in the design of this mousetrap car.

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3. ​

Check out these cars, what makes some unique?

Faster Cars Have What Qualities?

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Slow Cars, for distance have what Qualities?

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• Keep in mind everyone is the class will get the same material, but for students who complete their first car, they may bring in supplies to build a second unique car.

From this point forward, you should plan with your performance goal and design & material choices in mind. On a piece of blank or loose-leaf paper, sketch your final design. Below are some examples THE MORE DETAIL THE BETTER - Measurements, Labels, Directions!!!!

Exit Ticket:

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What is your plan?

Material

Mouse Traps Bulk Pack

Drinking Straws Drinking straws

Washers Washers

Cotton string Spool

Cds - 100 pack CD

Dowel Rods Rods

Cable Ties Cable Ties

A 4 x 8 Piece of Corrugated Sheets

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As a team list your first 5 steps in the construction of your car and be sure to include the material in your description, what teammate (or both) will be responsible. Once complete you will receive the supplies for each step.

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When a particular step is completed you will get the material for the next step.

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5 - Build Day 1

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You will have 2 days to build your mousetrap car.

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Tasks Today (List the Tasks and Who is responsible)

• Cutting out the Frame OF THE CAR (5 / 4 / 3) points
• Attaching the axles (5 / 4 / 3) points
• Straightening out the Mousetrap Car Arm and creating and attaching the rod, if necessary(5 / 4 / 3) points
• Gluing my mousetrap car in the proper position on my car. (5 / 4 / 3) points

Steps 1 & 2 - 20 Minute Checkpoint

Exit = Be prepared to hold up your car

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What are we going to do between now and next class go get prepared to finish our car?

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What is our major problem or concern?

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How am I going to solve it:

6 - Build Day 2

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2nd Day To Build.

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Tasks Today (List the Tasks and Who is responsible)

• Measuring the String, creating a loop and connecting the string to the mousetrap rod. (5 / 4 / 3) points
• Attaching the Wheels to the Axles (5 / 4 / 3) points
• Creating a small hook to you axel and attaching it properly (5 / 4 / 3) points
• Testing your mousetrap car by just pushing it on a desk and making any necessary adjustments (5 / 4 / 3) points

Steps 1 & 2 - 20 Minute Checkpoint

7 - Race Day

TESTING: Testing methods will be as follow:

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RUN FOR DISTANCE:

• Vehicles will be placed at a designated start line centered at the end of the Main Street hallway.
• Operators will start the vehicles, as prescribed in the project constraints.
• Vehicles will run until their forward momentum stops or until the vehicle comes in contact with a wall.
• Runs will be recorded to the last whole foot traveled (ex – 24’ 6” will earn a score of 24’).
• Each vehicle will be given at least two runs, with the longest run counting toward the final score.

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RUN FOR SPEED:

• Vehicles will be placed at a designated start line centered at the end of the Main Street hallway.
• Operators will start the vehicles, as prescribed in the project constraints.
• Vehicles will be timed from the 5 foot line to the 25 foot line.
• Vehicles that do not cover the course or collide with a wall will earn a rating of “1.”
• Each vehicle will be given at least two runs, with the fastest run counting toward the final score.

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PERFORMANCE SCORE:

• After all runs have been completed, each category of vehicles will be divided into thirds.
• Performance points will be awarded as follows:
• Top third – earn a rating of “4,” worth 20/20 points.
• Middle third – earn a rating of “3,” worth 17.4/20 points.
• Bottom third – earn a rating of “2,” worth 14.8/20 points.
• Cars that do not complete the course (for speed), have a construction violation as detailed in the constraints or do not run at all – earn a rating of “1,” which is worth 12.2/20 points.

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8 - Reflection