Question

A small metal sphere has a mass of 0.11 g and a charge of -25.0 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? Express your answer with the appropriate units.

Answer 1

The two spheres are identical. This means the two spheres has same size and shape and, they have the same charge. Consider the mass of the sphere-1 is m, and has the charge q, and the mass of the sphere- 2 is m, and has the charge q The expression for the electric force between the two spheres is, 2 The sphere-1 falls towards the sphere-2 and moves in downward direction from a certain height (10.0 cm). Then the weight of the sphere-1 acts towards downward and the net force acts towards downwards The two sphere has same charges then the electro static force due to the sphere-2 on the sphere-1 acts in the upward direction because the sphere-2 repel the sphere-

The net force that acts on the sphere-1 is, k,q2 a1 kq,q2 mr =g The two sphere has same charges then, 12 25.0nC The masses of the two spheres are, The distance between the two sphere is, 10.0cm

Calculate the acceleration of the sphere-1 as follows: ka,4 98m/s 0-10 N m e mc2s.onc) (0.11g) (10.0cm) (9s lợ N. m 2 /C2 )(25.0x10-9C)(25.0x10"C) 9.8 m/s2 (0.11x10% kg)(10.0x10.2 m)2 4.68 m/s