Electroscope

Today in class we did the lab, electroscope. We needed: 4 plastic drinking straws that bend, 2 plastic 35 mm film cans, modeling clay, scotch tape, and a balloon. We first put enough modeling clay into the film canisters to fill them half way up. Then we place the straws in each canister, two in each. Then Bent the straws to make arms for each. We then took two 4 inch pieces of tape and put them on the table and leave one end off. We pulled the tape up quickly then quickly placed it on the arm of each of the straws in the two canisters. We then moved the two tapes so they are face to face and 6 inches apart. Then we moved the two cans closer together. The two tapes repelled each other. Next, we tore off two more pieces of tape off and pressed them together and then pulled them apart. Quickly we pulled the two tapes apart and placed them on the two remaining arms. These two tapes attracted each other. Next we blew up the balloon and rubbed it on our hair. The balloon repelled the piece of tape whose smooth side was in the middle of the two pieces of tape and repels the sticky side that was in the middle. From this lab we learned that positive electrons repel and opposites attract. The two pieces of tape we first put on the table and pulled off repelled each other because they both had the same charge. We also saw that the tapes we stuck together and pulled apart we attracted to each other because one was negative and one was positive.