AP Physics 2 / Unit 10: Electric Force, Field, and Potential
10.4 Electric Potential Energy
Notes
$$U_E=k\frac{q_1q_2}{r}$$
- Like charges: positive $U$ (decreases as they separate). Opposites: negative $U$.
- In a uniform field: $\Delta U=qE\Delta d$ along the field change.
Practice
Two positive charges are pushed closer. Their potential energy:
Work against repulsion.
The potential energy of a proton-electron pair is:
Opposite signs.
Electric potential energy is a:
Energy has no direction.
Ready for more? Take the Unit 10 test.