Which of these is true about a magnetic field? it has the same magnitude at every point. it points in the same direction as it would make a compass point. it has a magnitude at each point but no specific direction. it has the same direction at every point.

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?