An astronaut of mass 150 kg is floating freely (at rest) in outer space. She is holding a 25 kg can (not part of her mass mentioned earlier). She throws the can forward with a velocity of 12 m/s. How fast will she move backwards after she throws the can?

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?