Two 10-cm-diameter charged disks face each other, 30 cm apart. The left disk is charged to - 50nC and the right disk is charged to + 50 nC . A) What is the electric field E⃗ , both magnitude and direction, at the midpoint between the two disks?
Express your answer to two significant figures and include the appropriate units.
B) What is the force F⃗ on a -1.4 nC charge placed at the midpoint?
Express your answer to two significant figures and include the appropriate units.

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