Two styrofoam balls with the same mass m = 9.00 × 10−8 kg and the same positive charge q are suspended from the same point by insulating threads of length l = 0.705 m. the separation of the balls is d = 0.0221 m. what is the charge q?

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)