1. Electric Force
Holt: Chapter 17-2
Pages

2. Electric Force
Electric force - force exerted between two charged objects  measured in Newtons
The closer the charges the greater the force between them.

3. Electric Force
Coulomb’s Law (1780’s) – electric force between 2 objects
Felectric = kc •q1•q2 r2
q1 = charge #1
q2 = charge #2
r = distance between charges
kc = Coulomb’s Constant in N•m2/c2
 8.99 x 109 N• m2/c2

4. Electric Force Force is a vector quantity (magnitude and direction)
Force goes exactly between 2 objects in a straight line

5. Electric Force Field force = no contact needed
Inversely proportional to the square of the distance of separation, bigger distance = less force.

6. Electric Force Differences between electric and gravitational forces
1. Electric attracts / repels and
Gravitational = always attracts
2. Electric is stronger than gravitational
Charge to overcome gravitational force is small

7. Electric Force Principle of superposition
→ Resultant force on any one charge equals vector sum of the individual forces exerted on that charge by all of the other individual charges that are present.

8. Electric Force Net external force = 0 N
In electrostatic situations the equilibrium position of a charge is the location in which the net electric force on the charge = 0 N