A4000 kg elephant is riding a bike at 4.0 m/s. a zebra runs out and the elephant has to slam its breaks. if the bikes breaks exert a force of 1400 n how far will it take the bike to stop

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?