1. Friction 500 On Your Mark, Get Set, Go!

2. GPS S8P3. Students will investigate relationship between force, mass, and the motion of objects. b. Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction.

3. EQ How does friction change with different surface textures? Real World Application: When designing a race car, what do the engineers need to think about in terms of friction? How does friction change with different surface textures? Real World Application: When designing a race car, what do the engineers need to think about in terms of friction?

4. Background: Friction is a force that opposes motion between two surfaces in contact. Friction is what causes a rolling object to slow down and eventually stop. In this lab we will explore how friction changes with different surface textures and apply it to a real world application – race cars! Friction is a force that opposes motion between two surfaces in contact. Friction is what causes a rolling object to slow down and eventually stop. In this lab we will explore how friction changes with different surface textures and apply it to a real world application – race cars!

5. Instructions Construct a ramp using a small piece of cardboard provided and a couple of books. Collect a yard stick to measure how far your car rolls Adjust your ramp so that the car stays on your table and doesn’t roll off the edge. Construct a ramp using a small piece of cardboard provided and a couple of books. Collect a yard stick to measure how far your car rolls Adjust your ramp so that the car stays on your table and doesn’t roll off the edge.

6. Place your car at the top of the ramp and make sure you mark the place you are holding your car at. It is important to release your car at the same place each time in order to collect good data. Let the car go and measure from the bottom of the ramp to where the car stopped. Make sure you always measure to the same place. It could be the back or the front of the car, just make sure it’s the same. We want good data! Record time from start to stop. Repeat a total of 3 times recording the distance in the table below.

7. =The Friction 500= Smooth Desk Time from start to stop (s) Distance traveled (cm) Average Speed (cm/s) Trial 1 Trial 2 Trial 3 Average

8. =The Friction 500= Sand Paper Time from start to stop (s) Distance traveled (cm) Average Speed (cm/s) Trial 1 Trial 2 Trial 3 Average

9. ClothTime from start to stop (s) Distance traveled (cm) Average Speed (cm/s) Trial 1 Trial 2 Trial 3 Average =The Friction 500=

10. Conclusion 1.Which surface had the most friction? Why? Explain how you know. 2. What would you predict would happen if you had a heavier car? 3. What causes friction? Draw microscopic picture of two surfaces in contact to help. 4. What two types of friction are there? Which one is evident in this experiment? 1.Which surface had the most friction? Why? Explain how you know. 2. What would you predict would happen if you had a heavier car? 3. What causes friction? Draw microscopic picture of two surfaces in contact to help. 4. What two types of friction are there? Which one is evident in this experiment?

11. Real World Application When designing a race car, what do the engineers need to think about in terms of friction?

12. NASCAR Video http://science360.gov/obj/video/7fdabae3- a9f2-4ed0-8059-16da6ad2ea72/science- speed-friction-heat http://science360.gov/obj/video/7fdabae3- a9f2-4ed0-8059-16da6ad2ea72/science- speed-friction-heat

13. Closing I care why? You will explain relevancy of the concept to your life or how you might use it. Write your response on the sticky note provided.