A ball rolls across the floor. Because of friction, the ball will eventually slow down and come to a stop. Which of the following is evidence of energy transfer resulting from the change in the motion of the ball?
Different surfaces create different amounts of friction.
The ball moves in the same direction as it rolls across the floor.
Energy sets the ball in motion.
The ball and the floor gain a small amount of heat energy.

A2-kg bowling ball is 2.5 meters off the ground on a post when it falls. just before it reaches the ground, it is traveling 7 m/s. assuming that there is no air resistance, which statement is true?

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

What is the increase in density of a medium due to wave travel?