A 111 kg111 kg horizontal platform is a uniform disk of radius 1.97 m1.97 m and can rotate about the vertical axis through its center. A 68.7 kg68.7 kg person stands on the platform at a distance of 1.11 m1.11 m from the center, and a 25.3 kg25.3 kg dog sits on the platform near the person 1.41 m1.41 m from the center. Find the moment of inertia of this system, consisting of the platform and its population, with respect to the axis.

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