Hello, I am having trouble understanding these 5 questions. If I could get the answers with explanation it would really help me. Thank you.

1. A tiny, glass sphere has a charge of +24.3 nC. A metal ball bearing, which is 4.00 cm above the glass sphere, experiences an electric force of magnitude 0.0130 N. What is the ball bearing's charge? Assume it is positive.

2. In the figure below, the distance between charges A and B and the distance between charges B and C are both 6.00 cm.

If A = 5.00 nC, B = -6.50 nC, and C = 4.50 nC, what is the net electric force on A? The magnitude to be exact

A + B C +10 nC 10 nc + b a + 5.0 nC+ 4.0 cm 2.0 cm 3.0 cm 3.0 cmH = 1.0 m 1.0 m