Section+Review

Section 1-1 Forces and Electrical Charges

In Ancient Greece around __B.C. Thales rubbed a piece of__ ? __with some cloth to see the effects of static electricity.__ ? __years later around 1570 an englishman named William ?__ __repeated the same experiment. He called it__ ? after the Greek word for amber.

? electricity __- is an electrical charge caused by an imbalance of electrons on the surface of a material. It is an electrical charge that builds up due to friction between two dissimilar materials. Friction removes some electrons from one object and deposits them on the other.

Name three examples of static electricity 1. 2. 3.

Define.__ Electrical charge__-__

Unlike charges__-__

Like charges__-

Unlike charges attract each other, where like charges__ ?__. The Fundamental Law of__ _? __: Like charges and unlike charges__ _? . Simulator [|__http://qbx6.ltu.edu/s_schneider/physlets/main/es_02.shtml__]

What is Coulomb’s Law?

If an object gains electrons it becomes __?__ charged. If an object loses electrons it becomes __?___ charged.

What is net charge? What is static discharge? What is a Van de Graaff generator?

In 1734, a French scientist named __?__ __Du Fay theorized that there are__ ? __types of electricity, which he called ?__ and _? __. Benjamin Franklin signed the ?__ of __,? but he was also a pioneer for electrical science. What did he believe that was different than Du Fay?

Franklin called the excess of an electrical charge ? and an absence of charge ?__ __.

What types of materials give off a positive charge?

What types of materials give off a negative charge?__

Check your Understanding Questions__

2. If you rub hard rubber with a piece of wool, what charge is on the rubber?
 * 1) As you move two charged cello tapes closer together, do the forces between them become greater or smaller?

3. Explain why, after combing, your hair is sometimes attracted to your comb.