How does friction generate static electricity? a. Friction heats the materials, thus causing electricity. b. Rubbing materials together displaces atom...
CK-12 Physics Concepts - Intermediate Answer Key Chapter 16: Static Electricity 16.1 Forces on Charged Objects Review Questions 1. How does friction generate static electricity? a. Friction heats the materials, thus causing electricity. b. Rubbing materials together displaces atoms, causing sparks to fly. c. Rubbing materials together can strip electrons off atoms, causing one material to become positive and the other to become negative. d. Rubbing materials together causes neutrons and electrons to trade places. e. None of the above. 2. What electrical charge does an electron have? a. A negative charge. b. A positive charge. c. A neutral charge. d. May be any of the above. e. None of the above. 3. What happens when opposite charges get close to each other? a. They repel each other. b. They attract each other. c. Nothing happens. d. They attract surrounding objects. e. They repel surrounding objects. 4. What is an electrical conductor? a. A material that allows electrons to travel through it freely. b. A material that doesnβt allow electrons to travel through it freely. c. A material that melts at low temperature. d. A material that creates free electrons. e. None of the above. 5. Which of the following is a good insulator of electricity? a. Copper b. Iron c. Rubber d. Salt water e. None of these. Answers
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16.2 Coulombβs Law Review Questions 1. Suppose that two point charges, each with a charge of +1.00 C are separated by a distance of 1.0 m. a. Will they charges attract or repel? b. What is the magnitude of the force between them? c. If the distance between them is doubled, what does the force become? 2. What is the electrical force between two balloons, each having 5.00 C of charge, that are 0.300 m apart? 3. Two spheres are charged with the same charge of -0.0025 C and are separated by a distance of 8.00 m. What is the electric force between them? 4. A red foam ball and a blue foam ball are 4.00 m apart. The blue ball has a charge of 0.000337 C and is attracting the red ball with a force of 626 N. What is the charge on the red ball? Answers 1. a. Since both charges are positive, they will repel. ((9.0Γ109
πΎπ1 π2
ππ2 )(1.0πΆ)(1.0πΆ)) πΆ2
b. Using πΉπ = π2 βΆ πΉπ = βΆ The magnitude of force is 9x109 1.0π N. c. If the distance is doubled, the force is reduced by 4: The new force: 2.25x109 N. 2. Using πΉπ =
