What is the magnitude?

Question

Two very small spheres are initially neutral and separated by a distance of 0.69 m. Suppose that 1.9 x 10^13 electrons are removed from one sphere and placed on the other. What is the magnitude of the electrostatic force that acts on each sphere?

thank you

Answer 1

F = k * |q1 * q2| / r^2

k = 1 / (4 * pi * epsilon0) = 8.987*10^9 (in the proper MKS units)

epsilon0 = 8.854*10^-12 C^2/(N m^2)

q = 1.9*10^13 electrons * 1.602*10^-19 C/electron =

3.044 microCoulomb

F = 8.987*10^9 * (3.044*10^-6)^2 / 0.69^2

F = 0.175 N

You should double check my math.

The constant epsilon0; you look up in any Physics book -- the same goes for the charge on an electron.

.