1. Folk wisdom says that a cat always lands on its feet. If a cat starts falling with its feet up, how can it land on its feet without violating the law of conservation of angular momentum?

2. A uniform rod of mass M and length L lies on a horizontal frictionless table. A piece of putty of mass m = M/4 moves along a line perpendicular to the rod, strikes the rod near its end, and sticks to the rod. Describe qualitatively the subsequent motion of the rod and putty.

3. Explain why a helicopter with just one main rotor has a second smaller rotor mounted on a horizontal axis at the rear as in Figure. Describe the resultant motion of the helicopter is this rear rotor fails duringflight.