1. Ralph who has a mass of 75 kg, is accelerated to 3m/s². How much force was applied to him?

2. An elevator carries 15 persons, each with an average mass of 50 kg, to a height of 20 m. How much work is done by the elevator?

3. A 7 kg bowling ball is moving on a bowling lane with a velocity of 5 m/s. What is the kinetic energy of the ball at that instant?

4. A football of mass 2.5 kg is lifted to the top of a cliff that is 50m high. How much potential energy does the football gain? ​