Question

what is the strength of an electric field that will balance the weight of a 8.0 g plastic sphere that has been charged to -1.2 nc ?

Answer 1

W = M g weight of sphere

E Q = W E is strength of field and Q is charge on sphere

M g = E Q

E = M g / Q strength of field required

E = .008 kg * 9.80 m/s^2 / 1.2 * 10E-9 C

E = 6.53 * 10^7 N/C strength of field required