Presentation on Electricity

Science Project

May 7, 2006

Group Members :

Positions :

Main Presenter : ___________Scientist Reader: _______________
Holder-upper-person-thingy : ____________
Experiment performer : ______________

Time : 5-7 min

Materials : Sketch pad (large), balloon or comb, cereal (“o” shaped or puff), string, wool sweater / dry hair

Procedure :

1. Tie a piece of the cereal to one end of a 12 inch piece of thread. Find a place to attach the other end so that the cereal does not hang close to anything else. (You can tape the thread to the edge of a table but check with your parents first.)
2. Wash the comb to remove any oils and dry it well.
3. Charge the comb by running it through long, dry hair several times, or vigorously rub the comb on a wool sweater.
4. Slowly bring the comb near the cereal. It will swing to touch the comb. Hold it still until the cereal jumps away by itself.
5. Now try to touch the comb to the cereal again. It will move away as the comb approaches.
6. This project can also be done by substituting a balloon for the comb.

Explanation : (To be written down on the sketch pad…)
Combing your hair moved electrons from your hair to the comb. The comb had a negative charge. The neutral cereal was attracted to it. When they touched, electrons slowly moved from the comb to the cereal. Now both objects had the same negative charge, and the cereal was repelled.
Dilemma : Where are we going to attach the string to???


Sketch Pad – 6 pages

1st page : Our Presentation on Static Electricity (names)

2nd page : Materials and Illustrations
3rd page : “Step 1 : Gain a static charge. Rub the balloon or plastic comb on dry hair or a woolen sweater. (diagram)What’s happening : This gives the balloon a negative charge. Because negative electrons are the esiest to come off when rubbed.

“Now that the balloon is charged, we move on to the next part of the experiment”

4th page : Magentism .Put the charged object near to the cereal. (diagram) The balloon and the cereal are attracted. This is because…

What’s happeneing : The neutral/positive cereal is attracted to the negatively charged balloon. They stick together because they are in a sense opposites. The negative electrons from the balloon are slowly being transferred to the cereal.

5th page : It dropped. -> Repulsion. Now that the cereal is finished charging and is charged with negative electrons it has dropped.