1. Chapter 20 review

2. The formula: F = KqAqB d2 F = force in Newtons
K = 9 x 109 (it is a constant)
qA = charge of one object
qB = charge of the other object
d = distance in meters

3. Example:
Two particles, one with a charge of -2 x 10-6 and the other with a charge of 5 x 10-6, are separated by 0.5 meters. What is the force between them?
Remember – no negatives in the formula and don’t forget to square the distance!

4. The set-up Notice no negatives and the distance is squared
F = (9 x 109) (5 x 10-6) (2 x 10-6)
0.52
Notice no negatives and the distance is squared

5. What attracts and what repels??
Positive and positive? Negative and positive? Negative and negative?

6. Net Charges
A summary of the charges left over after all positive and negatives have ‘cancelled ‘ each other out

7. Conductors? Carry electricity easily
Looks like: note the even charge distribution

8. Insulators? Slows down or impedes electrical flow
Looks like: note the uneven charge distribution

9. Creating electricity by…
Friction – you need contact and movement
Conduction – you need contact
Induction – in this case, you move a charged object close to two neutral objects, and the charges will move…

10. YOU are now ready