Serway & Jewett — Angular Momentum: Problem 24

Figure P11.13 represents a small, flat puck with mass \( m = 2.40 \text{ kg} \) sliding on a frictionless, horizontal surface. It is held in a circular orbit about a fixed axis by a rod with negligible mass and length \( R = 1.50 \text{ m} \), pivoted at one end. Initially, the puck has a speed of \( v = 5.00 \text{ m/s} \). A \( 1.30\text{-kg} \) ball of putty is dropped vertically onto the puck from a small distance above it and immediately sticks to the puck. (a) What is the new period of rotation? (b) Is the angular momentum of the puck–putty system about the axis of rotation constant in this process? (c) Is the momentum of the system constant in the process of the putty sticking to the puck? (d) Is the mechanical energy of the system constant in the process?