Three positive charges are located along a line, as in the diagram. The 0.10-C charge at point A is 2 m to the left of the 0.02-C charge at point B, and the 0.04-C charge at point C is 1 m to the right of point B.
a. What is the magnitude of the force exerted on the 0.02-C charge by the 0.10-C charge?
b. What is the magnitude of the force exerted on the 0.02-C charge by the 0.04-C charge?
c. What is the net force exerted on the 0.02-C charge by the other two charges?
d. If we regard the 0.02-C charge as a test charge used to probe the strength of the electric field produced by the other two charges, what are the magnitude and direction of the electric field at point B?
e. If the 0.02-C charge at point B is replaced by a 0.06-C charge, what are the magnitude and direction of the electrostatic force exerted on this new charge? (Use the electric field value to find this force.) 

+0.10 C (+) A +0.02 C + B SP1 Diagram 2m +0.04 C (+) 1 m