1. Three point charges are placed on the x-axis. The first charge is +2.0nC at the origin, the second -2.0nC to the right at x= 50 cm, and the third is +4.0nC at the 100 cm mark. What are the magnitude and direction of the electrostatic force which action the charge at the origin?
2. A foam ball of mass 0.150 g carries a charge of -2.00nC. The ball is placed inside a uniform electric field, and is suspended against the force of gravity. What are the direction and magnitude of the electric field?