Two negative charges, Q = -30 \mu C are placed on the x-axis at x = +0.25 m and x = -0.25 m.
1. How much energy does it take to assemble these two charges?
2. You place an unknown charge on the y-axis at y = 0.5 m and find that the electric potential is 0 V at the origin. What is the unknown charge?
3. If you place a -2 \mu C charge at the origin, what is the x-component of the force on it from the other three charges?
4. If you place a -2 \mu C charge at the origin, what is the y-component of the force on it from the other three charges?