Unit 8: Electric Charge and Electric Force

Unit 8: Electric Charge and Electric Force in AP Physics 1 introduces the fundamentals of electrostatics, focusing on the properties of electric charge and the forces between charged objects.

Key concepts include:

Electric Charge:

Two types: positive and negative.
The principle of charge conservation: total charge remains constant in a closed system.
Charge is quantized, with the elementary charge
𝑒
=
1.6
×
1
0
−
19
 
𝐶
e=1.6×10
−19
C.
Coulomb’s Law:

Describes the force between two point charges:
𝐹
=
𝑘
𝑒
∣
𝑞
1
𝑞
2
∣
𝑟
2
F=k
e
​

r
2

∣q
1
​
q
2
​
∣
​

where
𝐹
F is the force,
𝑞
1
q
1
​
and
𝑞
2
q
2
​
are charges,
𝑟
r is the separation, and
𝑘
𝑒
k
e
​
is Coulomb’s constant (
8.99
×
1
0
9
 
N
\cdotp
m
2
/
C
2
8.99×10
9
N\cdotpm
2
/C
2
).
Electric Force:

A vector quantity, with direction determined by the charges’ signs (attraction or repulsion).
Similarities and differences between electric force and gravitational force.
Conductors and Insulators:

Understanding how charges distribute in different materials.
This unit provides a foundation for exploring electric fields, potential, and the behavior of charged particles in subsequent topics. Students apply these principles to analyze interactions between charged objects and solve electrostatics problems.