Answer:
9 x 10^-12 c
Explanation:
q1 = 6 C
d = 0.3 m
q2 = ?
F = 5.4 N
As te force on the second charge is in the positive X axis direction so the charge on the second particle is positive in nature.
F = K q1 q2 / d^2
5.4 = ( 9 x 10^9 x 6 x q2) / (0.3 x 0.3)
5.4 x 0.3 x 0.3 = 54 x 10^9 x q2
q2 = 9 x 10^-12 C