Answer:
-7.89 * 10^(-9) C
Explanation:
Parameters given:
q1 = 2.42 nC = 2.42 * 10^(-9) C
Distance between q1 and q2 = 5.33 m
q3 = 1.0 nC = 1 * 10^(-9) C
Distance between q1 and q3 = 1.9 m
Distance between q2 and q3 = 5.33 - 1.9 = 3.43 m
The net force acting on q3 is:
F = F(q1, q3) + F(q2, q3)
F = (k*q1*q3)/1.9² + (k*q2*q3)/3.43²
F = (9 * 10^(9) * 2.42 * 10^(-9) * 1 * 10^(-9))/3.61 + (9 * 10^(9) * q2 * 1 * 10^(-9))/11.7649
F = 6.033 * 10^(-9) + 0.765*q2
If the net force is zero:
0 = 6.033 * 10^(-9) + 0.765*q2
-0.765*q2 = 6.033 * 10^(-9)
=> q2 = -[6.033 * 10^(-9)]/0.765
q2 = -7.89 * 10^(-9) C
