1. ELECTROSTATIC FORCE ELECTROSCOPE- a device used to determine the charge on an object

2. - - - + Charge by conduction- (direct contact) Comb is negatively charged Comb repels extra electrons on top leaving it positive. Leaves collect electrons making them negatively charged Leaves separate

3. Charge by Induction Rod is positively charged. Rod is brought near the top without touching it. Electrons are drawn to the top. The leaves are left positively charged. The leaves repel

4. Charging Spheres

5. COULOMB’S LAW The force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. F(n) Q 1 Q 2 (C 2 ) d (m) F(n)

6. Coulombs Law F e = kq 1 q 2 r 2 F e =electrostatic force (Newtons) q = charge (coulombs) r= distance (meters) k= electrostatic constant 8.99 x 10 9 Nm 2 /C 2

7. EXAMPLE A -6μC charge and a -3μC charge are 3.0cm apart. What is the electrostatic force between them? F= 8.99x 10 9 (-6x10 -6 C)(-3x10 -6 C) (0.03m) 2 F=179.8N (repulsive force) If F is (+) then this is a repulsive force If F is (-) then this is an attractive force

8. USES Static can be used to clean pollutants out of gases released from smoke stacks

9. LASER PRINTER Static keeps the toner on the paper to create images or letters.