Think of our milky way galaxy as a flat disk of diameter 100,000 light-years. suppose we are one of 1000 civilizations, randomly distributed through the disk, interested in communicating via radio waves. how far away would the nearest such civilization be from us (on average)?

The magnets would be | n s | and | s n|

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