A ball with a mass of 150 g which contains 4.30x108 excess electrons is dropped into a vertical shaft with a height of 150 m. At the bottom of the shaft, the ball suddenly enters a uniform horizontal magnetic field that has a magnitude of 0.290 T and direction from east to west. Part A If air resistance is negligibly small, find the magnitude of the force that this magnetic field exerts on the ball just as it enters the field. Use 1.602x10-19 C for the magnitude of the charge on an electron. F = N Submit Request Answer Part B Find the direction of the force that this magnetic field exerts on the ball just as it enters the field. O from north to south O from south to north Submit Request Answer