Question

What must the charge (sign and magnitude of a particle of mass 1.48 g be for it to remain stationary when placed in a downward-directed electric field of magnitude 640 n/c ?use 9.81 m/s2 for the magnitude of the acceleration due to gravity?

Answer 1

What is the magnitude of an electric field in which the electric force on a proton is equal in magnitude to its weight?
Use 1.67×10-27 kg for the mass of a proton, 1.60×10-19 C for the magnitude of the charge on an electron, and 9.81 m/s^2 for the magnitude of the acceleration due to gravity.