Aboy drops a ball from an observation tower. the ball hits the ground in 5.0 s. what is the ball's velocity at the time of impact?
a. 0 m/s
b. 98 m/s
c. 49 m/s
d. 123 m/s

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

Efficiency is the ratio of to for a system a)power in to power in b)power in to power out c) power out to power out d) power out to power in