When you push a 1.87-kg book resting on a tabletop, it takes 2.02 n to start the book sliding. once it is sliding, however, it takes only 1.47 n to keep the book moving with constant speed. what is the coefficient of static friction between the book and the tabletop?

An electron moving at 5.06 103 m/s in a 1.23 t magnetic field experiences a magnetic force of 1.40 10-16 n. what angle does the velocity of the electron make with the magnetic field? there are two answers between 0° and 180°. (enter your answers from smallest to largest.)