A disk of mass m slides with negligible friction to the right with speed vi on a horizontal table. The disk collides elastically with a uniform rod of length l that is at rest and free to pivot about one end, as shown in Figure 1 above. The disk rebounds to the left with speed vf , and the rod rotates with friction and stops at a final angle 0f from its initial position, as shown in Figure 2. Question Immediately after the collision, the rod has angular speed , and the rod comes to rest a time after the collision. If the rotational inertia of the rod about the pivot is , the average torque exerted on the rod by friction while the rod is coming to rest is Responses the fraction I omega, over delta t the fraction 2 I omega, over delta t the fraction l omega, over l delta t, end fraction