Answer to Question #287712 in Electricity and Magnetism for HassanHass

Question

Two point charge Q1 and Q2 are 3m apart, and their combined charge is 20micro coulumb.

(a) if one repels the other with a force of 0.075N, what are the two charges?

(b) if one attract the other with a force of 0.525N, what are the magnitude of the charges?

Answer 1

$q_1q_2=\frac{Fr^2}k,$

a)

$q_1q_2=75,$

$q_1+q_2=20,$

$q_1=15~\mu C,$ $q_2=5~\mu C,$

b)

$q_1q_2=25,$

$q_1+q_2=20,$

$q_1=18.7~\mu C,$ $q_2=1.3~\mu C.$