Q1. A father (m = 92 kg) and son (m = 44 kg) are standing facing each other on a frozen pond. The son pushes on the father and finds himself moving backward at 3 m/s after they have detached. How fast will the father be moving?
Q2. A roller coaster (399 kg) moves from A (2.89 m above the ground) to B (24.5 m above the ground). Two non-conservative forces are present: friction does -2.57 x 104 J of work on the car, and a chain mechanism does +5.27 x 104 J of work to help the car up a long climb. What is change in the car's kinetic energy KEf - KEo from A to B?