Solve the following questions given below:
Question I: Two plane parallel conducting plates 15mm apart are held horizontal one above the other in air. The upper plate is maintained at a positive potential of 1500 V while the lower plate is earthed. Calculate the number of electrons which must be attached to a small oil drop of mass 4.9 x 10-15 kg if it remains stationary in the air between the plate (assume the density of the air is negligible in comparison to that of oil.)
Question II: If the potential of the upper plate is suddenly changed to -3500 V what is the initial acceleration of the charge drop?
I need help to determine the initial acceleration of the charge drop.