Competency #8
Answer and Explanation
If you rub your head on a balloon, and then place that balloon against the wall, the balloon sticks to the wall. Explain how this happens.
Answer:
When you rub the balloon on your head, you do work to separate charge. By rubbing the balloon on your head, you cause electrons to move from your hair the balloon. This makes the balloon negatively charged. When you move the negatively charged balloon towards the wall, the negative charges in the balloon repel the electrons in the wall, so that the surface of the wall becomes temporarily positively charged. The negative charges in the balloon are attracted to the positive charges and the balloon sticks. This is a temporary effect. With enough time, the excess charge on the balloon will dissipate into the air, and the balloon will return to neutral. Once the balloon is neutral, the distribution of charge in the wall will return to its original state, and there will be no more attraction. The balloon will fall to the floor.
