Question

A proton is moved from a position where the electric potential is 125 V to a position where the electric potential is 275 V. The magnitude of the charge on a proton is 1.602 × 10-19 C. What is the change in electric potential energy of the proton?
2.0 × 10-17 J
2.4 × 10-17 J
4.4 × 10-17 J
6.4 × 10-17 J

Answer 1

We determine the electric potential energy of the proton by multiplying the net electric potential to the charge of the proton. The net electric potential is the difference of the final state to the that of the initial state. So, it would be 275 - 125 = 150 V.

electric potential energy = 150 (1.602 × 10-19) = 2.4x10^-17 J