AP Physics 2 / Unit 10: Electric Force, Field, and Potential
10.1 Electric Charge and Electric Force
Notes
Coulomb's law: $\displaystyle F=k\frac{|q_1q_2|}{r^2}$, $k=9\times10^9$ N·m²/C².
- Like charges repel; opposites attract.
- Doubling the distance makes the force one-fourth.
Practice
Doubling both charges makes the force:
$q_1q_2$ both double.
Two charges are moved 3 times farther apart. Force:
Inverse square.
A proton and an electron:
Opposite charges.
Ready for more? Take the Unit 10 test.