posted by sammy .
A uniform electric field of magnitude 250 V/m is directed in the positive x direction. A +12.0-ìC charge moves from the origin to the point (x, y) = (20.0 cm, 50.0 cm). (a) What is the change in the potential energy of the charge–field system? (b) Through what potential difference does the charge move?
Work= force dot displacement
= E*q dot displacement
= 250i*12 dot (.50j + .20i)
I assume you know how to do the dot product.