Question

A projectile has a mass m and, of course, it is charged (q). The tube, has an electric field E as shown which deflects the projectile as shown. The mass enters the tube with a velocity v (tube length is L) and, due to the electric field, it will be deflected in an upward direction. For a projectile mass of 1.0x10^-10kg, an electric field strength of 1.0x10^6N/C, a plate length of 15mm, and a drop initial horizontal speed of 29m/s, calculate the drop charge necessary to result in a deflection of 1.3mm when it first emerges from the tube.