6. Calculate the electrostatic force for two charges qı = 4 uC , q2 = 5 uC, and d between
them r = 0.4 cm. Make sure you use meter as the unit for distance unit.

Any one please I will gladly appreciate it.

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?