Ch 16: Electrostatics
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Coulomb’s Law
electric charges that are not moving
Definition of new symbols
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e- = electron
p = proton
n = neutron
e+ = positron
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k = 9.0 x 109 N m2/C2
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Q1 , Q2 = charges
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Electric Force
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The electron
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1 e - = -1.602 x 10-19 C
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Like charges repel; opposite charge
attract
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Think-Pair-Share
smallest unit of charge, also referred to as e
negatively charged
Charge of 1 e- is -1e
The proton
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Figure 16-15
1 p = 1.602 x 10-19 C
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r = distance between Q1 and Q2
positive and negative charges
Figure 16-13
measured in Coulombs (C)
1 C is a lot of charge!
Charge Carriers
Similar form as gravitational force
(weird, huh?), except
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Coulomb’s contant
positively charged
Charge of 1 p is +1e
Charge is quantized!
Coulomb’s Law
with different constants
What is the electrostatic force between
an e- and a p in a Hydrogen atom, given
the radius of the H atom is 0.5x10-10 m?
(more relevant to future chapters)
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Illustrations of Coulomb’s Law
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Comb & Paper
Illustrations of Coulomb’s Law
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Electroscope
induction
Illustrations of Coulomb’s Law
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Van de Graaff generator & pie plates
conduction
Illustrations of Coulomb’s Law
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Flowing water & charged rod
Conductor versus Insulator
Conductor
e-’s travel
Insulator
charge separation
within molecules
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