41. a 2.5-g copper penny is given a charge of −2.0 × 10−9 c . (a) how many excess electrons are on the penny? (b) by what percent do the excess electrons change the mass of the penny?

Ithink the answer is c but then again i'm probably wrong

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

Answerit increases at a steady rate;