A small metal sphere has a mass of 0.15 g and a charge of -23.0 nC. It is 10.0 cm directly above an identical sphere that has the same charge. This lower sphere is fixed and cannot move. If the upper sphere is released, it will begin to fall. What is the magnitude of its initial acceleration? O 3.2 m/s 0.0032 m/s 0.032 m/s O 0.00032 m/s