Electric Potential Energy & Potential – AP Physics C E&M | ShowMeClass

V

Electric Potential Energy & Potential

AP Physics C: E&M · Unit 2: Electric Potential

Learning Objectives

Calculate V from point charges: V = kQ/r

Relate E to V: E = -dV/dr

Visualize equipotential lines

Calculate PE: U = kq1q2/r

Key Equations

Concepts

Equipotential lines are perpendicular to E-field lines.

V is scalar — just add contributions from each charge.

Work: W = -qΔV = -ΔU

Colors

Positive charges (+)

Negative charges (-)

Equipotential contours

V(r) graph

PotentialEquipotentialE-field

V =-

|E| =-

U_sys =-

V(x) ALONG HORIZONTAL AXIS

Configuration

|Q| (uC) 5

Separation d (m) 1.0

Probe r (m) 0.5

Display

Potential Analysis

Quick Quiz▼

1. V from a point charge Q at distance r is:

kQ/r kQ/r2 kQr kQ2/r

2. Equipotential lines are always:

Parallel to E-field lines Perpendicular to E-field lines Circular Straight

3. The relationship between E and V is:

E = V/r E = -dV/dr E = dV/dt E = V*r