Two oppositely charged but otherwise identical conductingplates of area 2.50 square centimeters are separated by adielectric 1.80 millimeters thick, with a dielectric constant of K=3.60. The resultant electric field in the dielectric is 1.20 * 10^{6} volts per meter. a) Compute the magnitude of the charge per unit area σ on the conducting plate.
b) Compute the magnitude of the charge per unit area σ1 on the surfaces of the dielectric.
c) Find the total electric-field energy U stored in the capacitor.

Ithink the answer would be 1,350!

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