100 POINTS PHYSICS PLEASE HELP

1: Let’s say you drop a 100 kg ball from the top of the stairs and by the
time it reaches the ground it has a velocity of 40 m/s. How much kinetic
energy would it have?

2: If a 63.5 kg person climbs a hill that is 1500 m and stands at the top
looking over the edge, what is their potential energy at that point?

3: If that 63.5 kg person went parachuting, jumped out of an airplane, and
reached a velocity of 80 m/s before opening their parachute, how much
kinetic energy would they have?

4: Look at the formula for potential energy. Why would that 63.5 kg person
have more energy if they walked up a 1500 m hill than if they walked 1500
m on a flat surface?