1) What eventually happens to the lady bug?                                 2

1) What eventually happens to the lady bug?

2. From Newton’s second law, a force will cause an…

3. When considering angular motion, a torque will cause an…

4. What must be the centripetal force that keeps the lady bug moving in a circle?

5. Why does this force eventually fail?

6. Observe the acceleration vector as you start. Describe how it changes.

7. Will the acceleration vector ever point directly to the center?

8. Why not? (the next steps might help you answer this question)

9. Describe the motion of the wheel:

10. What happened to the acceleration vector?

11. What is the net torque?

12.  Eventually the disc stops and the net torque is zero. This is because the breaking

torque changed as you can see in the graph. Why did it change?

13. Calculate the moment of Inertia for the disk with the given information.

14. Calculate what the applied force must have been.

15. Calculate the angular acceleration of the disk. Work in SI units, and then convert

to degrees / s2. Compare to the graph to check your answer.

16. Predict what will happen to the moment of inertia if you keep the mass of the

platform the same, but you create a hole in the middle (increase inner radius).

17. Set the inner radius equal to 2. Calculate the moment of inertia for this shape.

Set the disk in motion and check your answer by looking at the moment of inertia

Graph.

18. Even when the force on the platform changes, the moment of inertia graph

remains constant. Why?

19. What is the SI unit for angular momentum?

20. Calculate the angular momentum in SI units (you should have already calculated

the moment of inertia in part II).

21. Changing the inner radius automatically changes the angular velocity to 36

degrees / s. Why?