Question 1: Is the kinetic energy of the descending mass really negligible compared with that of the rotating objects as claimed? The ratio of the two kinetic energies is ½mv²/½Iω². This may easily shown to be:

½ mv²/ ½Iω² = m D²/4I,

Use a typical falling mass, m = 100 g, and your values for D and I_ring and compute the right-hand side of above equation. D and m must be expressed in the MKS system. Discuss.

Question 2: Does the uncertainty in the theoretical value of I_disk account for the discrepancy in the experimental and theoretical values of I_disk?

Question 3: Did you find different values of W_F for the three set-ups? If so, do the differences make physical sense?

Question 4: Discuss why I_ring is so much larger than I_disk when the two bodies are of about the same mass and dimensions.