A penny is dropped from the empire state building 381m up. What is the velocity when the penny hits the head of someone 2
meters tall?

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

Avoltaic cell converts chemical energy to

In addition to gravity, what is the other predominant force that affects the motion of a pendulum?