When does the gravitational force between two objects become noticeable 1. When the objects are closer together
2. when the objects are far apart
3. only if the mass of both objects with large
4.At least one of the objects has mass

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?