Suppose a ball has a potential energy of 5 j when you dropped it. what would be its kinetic energy just as it hit the ground?

As an object falls from rest, its gravitational energy is converted to kinetic energy. Kinetic energy in Joule would be equal to its initial potential energy.

P.E = K.E = 5 J

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j