A box sits on a platform supported by compressed spring. The box has a mass of 1.0 kg. When the spring is released, it does 4.9 I of work on the box, and the box flies upward. What will be the maximum height above the platform reached by the box before it begins to fall?

Ibelieve the answer you're looking for is

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