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Phys132 1

2/20/17 1 Physics 132

•  Theme Music: Maynard Ferguson High Voltage •  Cartoon: Wiley Miller

Non-Sequitur

February 20, 2017 Physics 132 Prof. E. F. Redish

The Electric Potential

2/20/17 Physics

132 3

V !r( ) = ΔU(!r )q

V !r( ) = kCqj!r − !rjj=1

N

∑

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Phys132 2

Foothold idea: Fields

•  Test particle –  We pay attention to what force it feels.

We assume it does not have any affect on the source particles.

•  Source particles –  We pay attention to the forces they exert and assume

they do not move. •  Physical field –  We consider what force a test particle would feel if it were

at a particular point in space and divide by its coupling strength to the force. This gives a vector at each point in space.

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g = 1mWE→m

E = 1

qF all charges →q V = 1

qUall charges→q

elec

Explore the potential near a point charge

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https://phet.colorado.edu/sims/charges-and-fields/charges-and-fields_en.html