1.What is the kinetic energy of a runnibg boy whose mass is equal to 50 kg and a velocity of 5 m/s?

2.A man with a mass of 80 kg climbs set of stairs that are 5 m high? How much fravitational potential energy he gajned climbing up the stairs?

3. A roller coasrer of mass 3500 kg is rolling down track with a speed of 15 m/s What is its kinetic energy?

4.What is the potential energy of 50 kg rock sitting on a cliff 80 meters?​