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

Choose the correct general statement concerning the total potential and kinetic energy at any point along the arc of swing. the total energy at any point along the arc of swing of the pendulum is always less than 12 joules. the total energy at any point along the arc of swing of the pendulum is always more than 12 joules. the total energy at any point along the arc of swing of the pendulum is always equal to 12 joules. not enough information to determine