AP Physics Chapter 17Electric Potential and Electric Energy;

Capacitance

17-1 Electric Potential and Potential Difference•Potential or electrical potential is the potential per unit charge. Va=Pea/q •Potential difference is the difference is the work done by the electric force in moving a charge from point a to b. Vab=Va-Vb=-Wba/q•The SI unit for V is the volt… J/CV=PEb-Pea=qVba

17-1 (Cont’d)

• See chart and diagram p 504

• See Example 17-1 p505

17-2 Relation Between Electric Potential and Electric Field

• W=qVba

• W=Fd=qEd where d is the distance ll to field lines from point a to b…

• qV=qEd …so V=Ed and E=V/d

• See Example 17-2 p 506

17-3 Equipotential Lines

• Equipotential lines, or in 3-D, equipotential surfaces are areas of equal potential and are perpendicular to the electric field at any point. (See pg. 507 diagram.)

• There can be no electric field in a conductor in the static state.

17-4 The Electron-Volt …a unit of Energy

• 1eV= 1.6 x10-19J

• You must use the J value to calculate with KE=1/2 mv2

17-5 Electric Potential Due to Point Charges

• V=k Q/r = 1/(40) (Q/r) for a single pt. charge.

• See Example 17-3 p509• See Diagrams pg 509

See Example 17-4 and 17-5 p510/511

HOMEWORK• P522 1-8&10,13-14 due Tuesday BOP