An apple falls from a tree. How do its KE and GPE change as it falls to the ground?

Two identical bodies are sliding toward each other on a frictionless surface. One moves at 1 m/s and the other at 2 m/s. They collide and stick. The speed of the combined mass is:

A truck increases its speed from 8 m/s to 28 m/s over a distance of 120 m? How long does this take? Assume that the acceleration is constant.

A bomber flying at a constant velocity in level flight releases its bomb and hits a target on the ground. Neglecting air resistance, which one of the following is NOT true?

John is running up stairs rising vertically 4.0 m in 4.2 s. What is the power supplied by his muscles if his mass is 60.0 kg?

A driver, traveling at 22.0 m/s, slows down her car and stops. What work is done by the friction force against the wheels if the mass of the car is 1500 kg?

If you push a car with a force F, the force that the car exerts on you:

The maximum speed a car can round an 80-m radius horizontal curve without slipping is 20 m/s. How fast can this car round a 320-m radius curve on the same road?

A croquet mallet balances when suspended from its center of mass, as shown in the figure below. If the mallet is cut in two at its center of mass, how do the masses of the two pieces compare? 

A 1-kg block starts sliding up a frictionless 30o inclined plane with an initial velocity of 4.00 m/s. How far does the block go up the ramp before stopping?