Electric Force and Fields

Electric Force Definition: force of attraction or repulsion between charged particles Depends on: distance and amount of charge Who measured it: Charles Coulomb

Cheerios on Van De Graff Draw a picture of the cheerio demonstration. What happens and why? If the Van de Graff was negatively charged, what would happen if a negatively charged object was placed near it? Draw the force on the objects due to the generator Is the force stronger closer to the generator or father away? How do you know?

What would cause the electric force to become stronger? Think back to what electric force depends on… distance and amount of charge Decrease distance and increase charge

Electric Field Definition: area around a charged object in which other objects experience a force What does it show? Direction a positive charge would move What’s wrong with that? PROTONS DO NOT MOVE!!!

A few rules when drawing field lines Lines should never cross each other Number of lines indicate strength. The more lines, the greater the charge Why use field lines? It predicts movement of charged particles

1 positive object

1 negative object

Two positive charges Show the repulsion!!!

One positive and one negative Show the attraction!!!

+2 charge and -1 charge Note how many lines are coming out of the +2 charge and how many lines are coming into the -1 charge.