A 0.4kg ball has a velocity of 18m/s Calculate the kinetic energy of the ball

How much work would be required to stop the ball

A 7kg bowling ball is brought to a height of 1.5m
What is the increase of potential energy

How much work was required to lift the box to this position?
If the ball is dropped, calculate the velocity of the ball just before it hits the ground

The staples inside a stapler are kept in place by a spring with a relaxed length of 0.115m. If the spring constant is 51.0N/m, how much elastic potential energy( E. P.E) is stored in the spring when its length is 0.150m?

A roller coaster car with a mass of 1200kg starts at rest from a point (A) 20m above the ground.
a) What is the Potential energy of the car at point A?

b) If friction can be ignored, what will be the kinetic energy of the roller coaster at the bottom of the hill?

c) How fast is the roller coaster moving as soon as it reaches the bottom of the hill?

d) How much work must be done to stop the roller coaster as soon as it reaches the bottom of the hill? ( Explain)