Why does the girl’s body lurch forward, and at the same, time what happens to the skateboard?

The two required components for a generator are

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

Which lists the pairs of plates in order from least to greatest in terms of the work done to move the electron?