# Charge and Coulombs Law SPH 4 U Coulombs

• Slides: 28

Charge and Coulomb’s Law SPH 4 U

Coulomb’s Law The magnitude of the electrostatic force between two charged objects is: the charges on objects 1 and 2, measured in Coulombs

Coulomb’s Law The magnitude of the electrostatic force between two charged objects is: the separation between the centres of charge Note that Coulomb’s Law, like gravity, is an inverse square law.

Coulomb’s Law The magnitude of the electrostatic force between two charged objects is: constant k = 9. 0 x 109 N∙m 2/C 2

The Law of Electric Charges The direction of the force is determined by the Law of Electric Charges: • Objects with unlike charge attract. • Objects with like charge repel. • Charged objects attract (some) neutral objects.

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (a) Fe (b) Fg (c) Fe/Fg?

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (a) Fe

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (a) Fe

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (a) Fe

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (a) Fe Note that this force will be repulsive.

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (b) Fg

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (b) Fg

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (b) Fg

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (b) Fg Note that this force will be attractive.

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (c) Fe/Fg

Example 1 Two protons are separated by 1. 0 mm. What is the magnitude of: (c) Fe/Fg

Net Force If there is more than one charged object, the net force on any object is the vector sum of the forces acting on it. .

Example 2 What is the force on q 1?

Example 2 What is the force on q 1?

Example 2 What is the force on q 1?

Example 2 What is the force on q 1?

Example 3 What is the force on the -0. 60 m. C charge? 6. 0 cm

Example 3 What is the force on the -0. 60 m. C charge? 2 1 6. 0 cm 3

Example 3 What is the force on the -0. 60 m. C charge? 2 1 6. 0 cm 3

Example 3 What is the force on the -0. 60 m. C charge? 0. 675 N 1. 5 N

Example 3 What is the force on the -0. 60 m. C charge? 0. 675 N 1. 5 N

Example 3 What is the force on the -0. 60 m. C charge? 0. 675 N 1. 5 N

More Practice Textbook Questions • p. 335 -336 #2, 3, 5, 6, 7