Question: A negative charge (q=-0.55 coulombs) is plaved above the floor that has a postive charge. The floor creates a uniform electric field that has a magnitude of 105 N/C.
a) What is the magnitude and direction of the electric force caused by the floor on the negative charge?
b) If the charge is initially at a distance 2.5m above the plane, what will the change in electric potential energy(in joules) be if it is then moved to a distance 1.25m above the plane. (specify whether this change is postive/negative/zero).
Please explain each step in detail.