Two point charges of equal magnitude repel each other with a

Two point charges of equal magnitude repel each other with a force of 2.00 N when separated by 5.00 cm. Find the magnitude of the charge on each.

Solution

force

F = K*Q1*Q2 / d^2

given

F = 2N

Q1 = Q2 = Q

d = 5cm = 5*10^-2 m

F = K*Q^2 / d^2

Q = sqrt(F*d^2/K)

Q = sqrt (2* 5*5*10^-4/ 9*10^9)

Q = 7.45 x 10^-7 C