Which of the following examples of energy transfer CANNOT happen? A toy car rolling down a hill increases speed and then rolls to a stop.
A bunger jumper jumps from a bridge and goes up higher with each recoil.
A child playing on a swing moves fastest at the bottom of the swing's path.
A rock dropped from the top of a bridge increases in speed until it hits the water.

I think it’s the second one. sorry if im wrong :/

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