A ball is swung in a horizontal circle at a constant speed. Each circle takes 0.85 seconds to complete and the rope is 0.40 m long. What is the centripetal acceleration?

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.)