1. Physics Section 16.2 Apply Coulomb’s Law
Coulomb’s Law: The force between two charged particles varies directly as the magnitude of the product of the charges and inversely as the square of the distance between their centers.
Fe = magnitude of electrical force (N) q1 = charge on 1st particle (C) q2 = charge on 2nd particle (C) r = distance between centers of the particles (m) Kc = Coulomb’s constant x 109 N • m2/C2
Fe = Kc (q1 • q2) r2

2. example
An electron and a proton are separated by 5.3 X m. Find the magnitude of the electric force and the gravitational force between them.

3. example
Two point charges are repelled by a force of 35 N. Find the distance between the charges if their magnitudes are 75μC and 55μC.

4. What is the force on each charge?

5. Three charges lie along a line. One charge, q1 = 18μC is 1
Three charges lie along a line. One charge, q1 = 18μC is 1.5 m left of q2 = 24μC. Where should a 3rd charge, q3, be placed so that the system is in equilibrium?

6. Find the magnitude and direction of the force on q3

7. The electric force between two charged particles is a field force.
While gravitational and electric forces are similar, electrical forces can be either attractive or repulsive. Electrical forces are much stronger than gravitational forces.

8. Assignment
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Problems 1 - 5