#AP Physics 1: Electricity & Forces - Night Before Cram

Hey! Let's get you prepped for the AP Physics 1 exam. This guide is designed to be your quick, high-impact review, focusing on key concepts and strategies. Remember, you've got this! 💪

#⚡️ Electric Charge Fundamentals

#What is Charge?

• Charge is a fundamental property of matter, like mass. It comes in two types: positive (carried by protons) and negative (carried by electrons).
• Atoms are neutral when they have an equal number of protons and electrons.

#How Objects Become Charged

• Negative Charge: An atom gains extra electrons.
• Positive Charge: An atom loses electrons, resulting in more protons than electrons.

- **Dipoles:** Separation of charge within an object, creating partial positive and negative ends, even if the overall charge is neutral.

#Measuring Charge

• Charge is measured in coulombs (C).
• The charge of an object is always a multiple of the elementary charge (charge of one electron).
• Elementary charge (e) = 1.602 x 10^-19 C.

- "Point charge" refers to a charged particle where charge is concentrated at a single point.

#🧲 Electric Force: Coulomb's Law

#Coulomb's Law

• Describes the force between two charged particles. The force is attractive for unlike charges and repulsive for like charges.

• The magnitude of the electric force is given by:

  $$F = k \frac{|q_1 q_2|}{r^2}$$

  Where:

  • F is the electric force.
  • k is Coulomb's constant (8.99 x 10^9 Nm²/C²).
  • q1 and q2 are the magnitudes of the two charges.
  • r is the distance between the charges.