Question

A charge of 20 x 10-6 C is 20 cm from another charge of 60 x 10-6 C. (a) Find the force between them. (b) Determine the Ep midway between them.

Answer 1

a)

$F=\frac{k(q_1^2-q_2^2)}{r^2}=720~N,$

b)

$E=\frac{4k(q_1-q_2)}{r^2}=36~\frac{MV}m.$