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Ch 16: Electrostatics
electric charges that are not moving
Definition of new symbols
e- = electron
p = proton
n = neutron
e+ = positron
Coulomb’s Law
k = 9.0 x 109 N m2/C2
Coulomb’s con tant
Q1, Q2 = charges
measured in Coulombs (C)
1 C is a lot of charge!
r = distance between Q1 and Q2
Electric Force
Similar form as gravitational force
(weird, huh?), except
positive and negative charges
Like charges repel; opposite charge
attract
Figure 16-13 Figure 16-15
Charge Carriers
The electron
The electron
1 e- = -1.602 x 10-19 C
smallest unit of charg e, also referred to as e
negatively charged
Charge of 1 e- is -1e
The proton
The proton
1 p = 1.602 x 10-19 C
positively charged
Charge of 1 p is +1e
Charge is quantized!
Think-Pair-Share
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?
Coulomb’s Law
with different constants
(more relevant to future chap ters)
