Chapter 20 review

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

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!

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

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

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

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

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

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…

YOU are now ready