Coulombs Law An inverse square law Strength Which
Coulomb’s Law An inverse square law.
Strength Which force is stronger, GRAVITATIONAL ELECTROSTATICS? (Examples static cling in dryer and dry ink in paper copiers)
Which force is stronger? View the following videos: Cavendish torsion experiment Floating Bill Fun Fly Stick Fun with Static Electricity: Jedi Board Trick Electromagnetic Force by Brian Greene The Office ?
Law of Universal Gravitation A review from last semester… Where G = 6. 67 X 10 -11 N m 2 / kg 2
Using this… Find the force of the moon around the Earth MEARTH = 6 X 10 24 kg , m Moon = 7. 3 X 10 22 kg and the distance between them is 3. 9 X 108 m Plug in to Final answer is 1. 92 X 10 20 N
Origin of Law Charles Coulomb (1761) developed a similar apparatus to the torsional balance developed by Cavendish
The law Coulomb’s Law is Where Q is charge measured in Coulomb’s (large unit-- 3 to 5 coulombs in lightning) K is the dielectric constant which is variable for different materials. 9 X 10 9 in air (most common)
Example A positive charge of 1. 2 X 10 -6 Coulomb (also known as a micro-coulomb) and a 1. 6 X 10 -6 C negative charge separated by a distance of 20 cm (0. 20 m). (Remember k=9 X 10 9 N m 2/ C 2)
Inverse Square Law What happens to the force when you double a distance between charges? What happens to the force when you half the distance between charges?
- Slides: 9