Two long current-carrying wires run parallel to each other and are separated by a distance of 5.00 cm. if the current in one wire is 1.80 a and the current in the other wire is 3.40 a running in the opposite direction, determine the magnitude and direction of the force per unit length the wires exert on each other.

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