Hailey Physics Ch 20

A rubber rod can be charged negatively when it is rubbed with wool. What happens to the charge of the wool?

• the wool becomes positively charged

• the wool becomes negatively charged

• the wool is neutral

An apple contains trillions of charged particles. Why don't two apples repel each other when they are brought together?

• the apples both have negative charges only

• the apples both have positive charges only

• each apple contains equal numbers of positive and negative charges

You can charge a rubber rod negatively by rubbing it with wool. What happens when you rub a copper rod with wool?

• the copper rod becomes negative

• the copper rod becomes positive

• the copper rod remains neutral as long as it is in your hand because it is a conductor

A negative charge of -2.0x10^-4 C and a positive charge of 8.0x10^-4 C are separated by 0.30m. What is the force between the two charges?

• 1.6x10⁴ N

• 6.7x10⁴ N

• 1.6x10^-4 N

• 6.7x10^-4 N

How are electric forces related?

• electric force is directly related to each charge

• electric force is indirectly related to each charge

How are electric force and distance related?

• electric force is directly related to the distance between charges

• electric force is indirectly related to the distance between charges

• electric force is indirectly related to the square of the distance between charges

• electric force is directly related to the square of the distance between charges

A strong lightning bolt transfers about 25 C to Earth. How many electrons are transferred?

• 1.6x10²⁰ electrons

• -1.6x10²⁰ electrons

Two electrons in an atom are separated by 1.5x10^-10 m, the typical size of an atom. What is the electric force between them?

• 1.1x10^-8 N

• -1.1x10^-8 N

• 1.1x10⁸ N

• 1.1x10^-2 N