1. Rat Trap Racer Project #1 Land Transportation

2. Objectives By the end of the unit, the students will be able to: 1. State what Friction and Rolling Friction are 2. State how aerodynamics plays a role in your projects 3. Demonstrate how wheels play a role in your projects success 4. Demonstrate how to Construct a Rat Trap Racer for distance, speed, and climbing ability

3. What is Rolling Friction What is Rolling Friction? Answer: Rolling friction is caused primarily by the interference of small indentations formed as one surface rolls over another. This is the idea behind the frictional forces involved with wheels, cylinders, and spheres. Rolling friction is caused primarily by the interference of small indentations formed as one surface rolls over another. This is the idea behind the frictional forces involved with wheels, cylinders, and spheres. http://www.fearofphysics.com/Friction/fricti on.html

4. What is Friction What is Friction Friction is the "evil" of all motion. No matter which direction something moves in, friction pulls it the other way. Move something left, friction pulls right. Move something up, friction pulls down. It appears as if nature has given us friction to stop us from moving anything. Friction is actually a force that appears whenever two things rub against each other. Although two objects might look smooth, microscopically, they're very rough and jagged. Friction is actually a force that appears whenever two things rub against each other. Although two objects might look smooth, microscopically, they're very rough and jagged. As they slide against each other, their contact is anything BUT smooth. They both kind of grind and drag against each other. This is where friction comes from. As they slide against each other, their contact is anything BUT smooth. They both kind of grind and drag against each other. This is where friction comes from. But friction is not all bad. In fact, it has a lot to do with life as we know it here on Earth. Without it, we wouldn't be able to walk, sit in a chair, climb stairs, or use a mouse to surf the web. Everything would just keep slipping and falling all over the place. But friction is not all bad. In fact, it has a lot to do with life as we know it here on Earth. Without it, we wouldn't be able to walk, sit in a chair, climb stairs, or use a mouse to surf the web. Everything would just keep slipping and falling all over the place.

5. What is Aerodynamics Aerodynamics is the study of how air flows under, over, and around an object. Thinking about how aerodynamics will play a role in your vehicles in the design stage will help your vehicle to do better

6. Length of Car Matters Although you might not think it the length of the car matters for each different part. For example you want the longest swing of the rat trap arm for distance. Make the car long and add extensions to the arm. Remember that each revolution of the axle is a revolution of the tires so the larger the tires the further it will go. The distance isn’t tested for speed so make sure your vehicle doesn’t jump the line at the beginning.

7. Traction and Friction For the speed part you want friction at the beginning so there is not burning out. It is important your vehicles tires grab the ground to give it that boost. For speed you want a shorter wheel base and shorter swing arm so it pulls the string quicker. Wider tires help but you will still need something to help grab the tiles.

8. Climbing When it is time to construct your climbing vehicle it is all about torque and speed. You want your vehicle to twist the axle aggressively so it is important your rat trap uses both springs plus you will have a little head start before the ramp so you will be able to build some speed and get some momentum

9. Challenge Each student will design, sketch, and construct their own Rat Trap Racer using various materials and equipment in the Construction Lab. The Sketches are random ideas of your thoughts but there should be a minimum of 4. From those 4 sketches select 1, draw it in detail using a ruler and straight lines (no freehand drawing). Be sure to include dimensions on your Initial Drawings. When the project is complete you will be required to complete the evaluation form Your grade is broken down into 3 parts be sure to see the Evaluation part for further explanation. Each student will design, sketch, and construct their own Rat Trap Racer using various materials and equipment in the Construction Lab. The Sketches are random ideas of your thoughts but there should be a minimum of 4. From those 4 sketches select 1, draw it in detail using a ruler and straight lines (no freehand drawing). Be sure to include dimensions on your Initial Drawings. When the project is complete you will be required to complete the evaluation form Your grade is broken down into 3 parts be sure to see the Evaluation part for further explanation.

10. Challenge Your grade for part 1 depends on how close to your Initial Drawing you constructed your Rat Trap Racers. The closer it resembles your Initial Drawing, the better your grade will be. The more changes you make or extra pieces you add the lower your grade will be. There are no partners on this project; each student must make their own Car. Part 2 is each student will be provided with one (1) rat trap for all three projects. If your rat trap breaks during these projects I will not provide you with another one. Each Rat Trap Racer will be given one (1) week to be completed. If your vehicle is not completed by the due date it will not be accepted at all. If you have a vehicle that is halfway completed your car is to be tested as is and you will be given no extra time to work on them. If you are absent during these next weeks you will be given only one day for each absence to make up your work and it must be done before school at 7:10 in the morning. You will not be given class time to make up missed work. You cannot use the same car for all three tests. The cars must look different but can use the same principals if needed. These Rat Trap Racers must have a minimum of 3 vinyl designs and numbers using three different colors on each of them

11. Challenge The first Rat Trap Racer to be built is for distance. It absolutely has to go 30 feet minimum and from 30 feet you will be graded on how far it can go beyond it. Once your vehicle starts to move you cannot touch it or have a friend touch it in any way to correct it. These vehicles should estimate between 70 and 100 foot distances if you take your time and try hard. Next is for speed. We will time your car to see how fast it goes in a 15-foot distance. These cars should get times below 2 seconds. Once again this vehicle must have at least 3 vinyl designs on it using three different colors. You will have another 3 class periods to do this part. Testing on the fourth day. Finally this project is to go up the ramp the furthest distance with a minimum of 10 feet. You will be graded based on how far up the ramp beyond 10 feet it goes and once again you will have to create 3 more different designs using 3 colors of vinyl and place them on your car. You will have 3 class periods to work and the fourth is the test. The first Rat Trap Racer to be built is for distance. It absolutely has to go 30 feet minimum and from 30 feet you will be graded on how far it can go beyond it. Once your vehicle starts to move you cannot touch it or have a friend touch it in any way to correct it. These vehicles should estimate between 70 and 100 foot distances if you take your time and try hard. Next is for speed. We will time your car to see how fast it goes in a 15-foot distance. These cars should get times below 2 seconds. Once again this vehicle must have at least 3 vinyl designs on it using three different colors. You will have another 3 class periods to do this part. Testing on the fourth day. Finally this project is to go up the ramp the furthest distance with a minimum of 10 feet. You will be graded based on how far up the ramp beyond 10 feet it goes and once again you will have to create 3 more different designs using 3 colors of vinyl and place them on your car. You will have 3 class periods to work and the fourth is the test.

12. Challenge On testing day you will be given the class period to complete the objective. You will have ample time to do this project and testing and practicing is always allowed. There should be no excuses as to why your project is not completed and in working condition. There is no power on testing day unless specified by the instructor. You must do all work in class unless I give you permission to take it home. Be creative on this project and a nice design and creative effort will only increase your grade. Good luck On testing day you will be given the class period to complete the objective. You will have ample time to do this project and testing and practicing is always allowed. There should be no excuses as to why your project is not completed and in working condition. There is no power on testing day unless specified by the instructor. You must do all work in class unless I give you permission to take it home. Be creative on this project and a nice design and creative effort will only increase your grade. Good luck

13. Procedures Brainstorm ideas and sketch 4 of them onto 2 pieces of paper Brainstorm ideas and sketch 4 of them onto 2 pieces of paper Choose a design that you like the best, draw an initial drawing of it with dimensions Choose a design that you like the best, draw an initial drawing of it with dimensions Use the supplied materials to create the energy launcher Use the supplied materials to create the energy launcher Finish the energy launcher using a filler and any color paint you choose or vinyl Finish the energy launcher using a filler and any color paint you choose or vinyl

14. Evaluation Project Travels more than 30 feet Project Travels more than 30 feet Project travels 15 feet in under 6 seconds Project travels 15 feet in under 6 seconds Project travels up ramp 10 or more feet Project travels up ramp 10 or more feet Project looks like Initial Drawing with minimal changes Project looks like Initial Drawing with minimal changes Student shows above average effort Student shows above average effort Student shows above average safety skills Student shows above average safety skills 100 Points

15. Evaluation Project Travels more than 30 feet Project Travels more than 30 feet Project travels 15 feet in under 6 seconds Project travels 15 feet in under 6 seconds Project travels up ramp 10 or more feet Project travels up ramp 10 or more feet Project looks like Initial Drawing with moderate changes Project looks like Initial Drawing with moderate changes Student shows above average effort Student shows above average effort Student shows above average safety skills Student shows above average safety skills 75 points

16. Evaluation Project passes 2 of 3 challenges Project passes 2 of 3 challenges Project looks like Initial Drawing with very noticeable changes Project looks like Initial Drawing with very noticeable changes Student shows above average effort Student shows above average effort Student shows above average safety skills Student shows above average safety skills 50 points

17. Evaluation Project does not work Project does not work Project does not look like drawing at all Project does not look like drawing at all Student shows no effort Student shows no effort Student not allowed in class if not demonstrating proper safety skills Student not allowed in class if not demonstrating proper safety skills 0 points