A thin uniform rod of length and mass is hinged at its upper end to a friction-free…
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A thin uniform rod of length 1.2m and mass 1.5kg is hinged at its upper end to a friction-free pivot so it can swing in a vertical plane. The rod is initially at rest, hanging straight down. A 0.25kg ball travelling horizontally at 6.0m/s strikes the rod at its midpoint and sticks to it.
Neglect any forces other than those described.
(a) Determine the magnitude of the ball’s angular momentum about the pivot immediately before the collision.
(b) Calculate the angular speed of the rod–ball system immediately after the collision.
(c) After the collision the system swings upward. Determine the maximum angle from the vertical that the rod reaches before momentarily coming to rest.