#AP Physics C: E&M - Electric Potential & Energy Study Guide

Hey there! Let's get you prepped for the exam. This guide is designed to be your go-to resource, especially the night before the test. We'll break down the key concepts, highlight important formulas, and make sure you're feeling confident and ready to ace it!

#⚡ Electric Potential and Energy: The Big Picture

Electric potential difference is the driving force behind energy changes in electrical systems. When charges move between points of different potential, energy transforms between electric potential and kinetic forms, always following the law of energy conservation. Understanding these transformations is key to analyzing circuits and charged particle motion. Let's dive in!

#Changes Due to Electric Potential Difference

#System Energy Changes

• Moving a charged object between two points with different electric potentials changes the electric potential energy of the object-field system. This change is given by:

  $$\Delta U_{E}=q \Delta V$$

  Where:

  • $$\Delta U_{E}$$ is the change in electric potential energy (in joules).
  • $$q$$ is the charge of the object (in coulombs).
  • $$\Delta V$$ is the electric potential difference (in volts).

• Positive Charge Movement:

  • Moving a positive charge from a higher potential ($$V_1$$) to a lower potential ($$V_2$$) results in a negative $$\Delta U_{E}$$, meaning the system loses electric potential energy. Think of it like a ball rolling downhill - it loses potential energy. 🔋
  • Conversely, moving a positive charge from lower to higher potential results in a positive $$\Delta U_{E}$$, meaning the system gains electric potential energy.

• Kinetic Energy Connection:

  • A decrease in electric potential energy (negative $$\Delta U_{E}$$) corresponds to an increase in the object's kinetic energy. The 'lost' potential energy turns into motion!
  • An increase in electric potential energy (positive $$\Delta U_{E}$$) results in a decrease in the object's kinetic energy. The object slows down as it gains potential energy.

#Charged Object Movement

• The direction a charged object moves in an electric field depends on its charge and the field's direction.

• Positive Charges:

  • Positive charges (like protons) are accelerated from *higher ...