Thinking about Static Electricity 1. Sarah rubs a balloon on her hair. She touches the balloon to the wall and lets go. She sees that the balloon stays on the wall. If Sarah could see what is happening between the balloon and the wall, what would it look like? a. Draw a picture to show what you think is happening between the balloon and the wall right before the balloon sticks to the wall. Use pictures or symbols to show the interaction between the balloon and the wall. b. Explain what your picture shows. Include how your drawing shows the interaction between the balloon and the wall. Students in Mr. Miller's class watched a demonstration on electric charge. In the first example of an interaction, Mr. Miller brought two plastic rings together. The rings moved apart when they got near each other like in Figure A. In the second example of the interaction, the rings moved toward each other like in Figure B. Mr. Miller asked the students if the two Q O OO examples of interactions provided convincing evidence Figure A Figure B that both rings in each example were electrically charged. Here is what some students said: Faith: I think both examples provide evidence that all of the rings in both interactions were electrically charged. Milo: I think only the first example provides evidence that both rings in an interaction were electrically charged. Judd: I think only the second example provides evidence that both rings in an interaction were electrically charged. Fran: I think neither example provides evidence that both rings in an interaction were electrically charged. Write who you agree with the most and explain your reasoning.3. Five friends were trying out the new slide on the playground. The new slide is made out of plastic. They noticed that each time they reached the bottom of the slide, they got a small electric shock when they touched the ground. They wondered where the electric charge came from. This is what they said: Kevin: I think the charge can only come from the plastic side. Tanisha: Today I was wearing wool pants. I think the charge can only come from the pants. Jin-Sang: I think the charge could come from either the slide or the pants. Kerry: My pants rubbed against the plastic slide as I slid down. I think the rubbing creates charge. Marsha: Maybe the rubbing creates heat. The heat is what creates the electric charge. Write who you agree with the most and explain your reasoning. 4. Two negatively charged balloons repel each other; one is blue and the other green. Determine what would happen to the size of the repulsion force in each case (increase or decrease or remain the same) and explain why. Assume each case is independent of the others. a. The blue balloon is given even more negative charge than it had before. b. The blue and green balloons are both given even more negative charge than they had before. c. The blue balloon is brought closer to the green balloon. d. The distance between the blue and green balloon is doubled. e. The blue and green balloons both double their negative charge and the distance between them is doubled