1. How is static electricity different from current electricity?
May 8, 2009
If I rub a balloon on my head and slowly remove it, my hair stands on end. Why?
How is static electricity different from current electricity?

2. Q: What’s a Coulomb?
A coulomb is a unit to measure the amount of electrical charge in an object
1 Coulomb = ×1018 electrons
Coulomb's Law is one of
the basic ideas of electricity
in physics.

3. Q: What’s a Coulomb? Tells us 2 things:
As distance increases, the force between objects decrease.
As charges of two objects increase, the force between them increases.

4. Q: What’s a Coulomb?
The force between the objects can be positive or negative depending on whether the objects are attracted (+ force) to each other or repulsed (- force).

5. Q: What’s a Coulomb? Equation to represent Coulombs Law:
It looks scary, but think of Newton’s law of gravitation - F = G m1m2 / d2
F = k
q1x q2 r2

6. Coulomb’s Law
F = k
q1x q2 r2
F = force
k = constant (changes based on the medium of electron travel)
q = charge of objects (1 and 2)
r = distance between their centers

7. If I quadruple the distance between 2 objects, the electrical force between them will ____ by _____.
If I triple the charges of both objects, the electrical force between them will _____ by _____.
If I triple the charge of one object only, the electrical force between them will ___ by ___.
If I cut the charge of both objects in half, the force between them will ____ by ____.
If I decrease the distance between them by a factor of 5, the force between them will ___ by ____.

8. HOMEWORK Work on test review pages.
Page 1: Electricity Crossword (Required)
Page 2: Electric Power and Coulomb’s Law WS (Required)
Page 3: Circuit Review WS (Required)
Page 4: Electricity and Ohm’s Law WS (Not Required)
Page 5: Coulomb’s Law Practice WS (Not Required)
DON’T FORGET:
You will be required to read resistors based on their color bands!
Look over your notes!!!!!
Bellringers!!!!