A negative charge (q=-0.75 Coulombs) is placed above a floor that has a net positive charge. The floor creates a uniform electric field that has a magnitude of 95 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 positive/negative/zero)?