Charges and charging - Lesson

Do Now

Open Ended

Complete the sentence regarding the Fundamental Law of Charges: ________.

Open Ended

Sphere A is negatively charged; when placed next to sphere B they attract. What is the charge on sphere B?

Notes

3 ways to charge a neutral object

1. ​Charging by friction.

2. Charging by conduction.

3. Charging by induction.

Practice

Open Ended

Your cat rubs against a rubber balloon. What will be the charge on the balloon?________ Your cat's fur?_____________

Open Ended

You use three charged objects – A, B & C for an experiment on charges. During the lab you make the following observations: - When you bring object A near object B, the objects attract each other. - When you bring object A near object C, the objects repel each other. What would happen if object B & C were brought together?

Open Ended

Describe why an object can have a positive or negative charge?

Open Ended

What is the fundamental law of charges, and how does it work?

Multiple Choice

You use 3 objects- A, B, and C for an experiment on charges. What would happen if object B & C were brought together?

During the lab you made the following observation:

1. 1. A & B - attract each other.

2. 2. A &C - repel each other.

• Object B & C would repel each other

• Object B & C would attract each other

• Nothing would happen, since objects B & C are neutrally charged

• The oppositely charged objects A & C will repel each other

Multiple Choice

Use the following electrostatic series to answer the question: Rubber, Ebonite, Polyethylene (Plastic), Cotton, Silk, Wool, Glass, Acetate, Fur. What would happen if a polyethylene ruler was rubbed with a wool cloth?

• a) Nothing

• b) The polyethylene ruler would take the wool’s positive charges

• c) The wool cloth would take the polyethylene ruler’s negative charges

• The polyethene ruler would take the wool's negative charge.

Multiple Choice

What would happen if you used a cotton cloth to wipe your glass window clean?

• The glass window would become negatively charged

• The cotton cloth would become negatively charged

• The cotton cloth would become positively charged

• The glass window & cotton cloth would stay neutrally charged

Multiple Choice

Which statement is completely true?

• Fur rubbed with silk will become negatively charged because the silk will gain/receive negative charges

• Acetate rubbed with cotton will become positively charged because the acetate will gain/receive positive charges

• Ebonite rubbed with fur will become negatively charged because the ebonite will gain/receive negative charges

• Polyethylene rubbed with wool will become negatively charged because the polyethylene will lose positive charges & the wool will gain/receive these positive charges

Multiple Choice

You have 2 spheres made of ebonite. You rub one with rubber & the other with cotton. What would happen if you brought the two spheres together?

• Nothing, they are both neutrally charged

• They will repel

• They will attract

• Nothing, they both carry no charge

Multiple Choice

You have 2 spheres made of ebonite. You rub one with wool & the other with silk. What would happen if you brought the two spheres together?

• Nothing, they are both neutrally charged

• They will repel

• They will attract

• Nothing, they both carry no charge

Multiple Choice

4. Spheres A & D are then set up side by side, as well as spheres B & D.  Which diagram below correctly shows what would happen?