This is my school project for Physics. Yes, it is my homework for this year’s lebaran holiday. But I worked on it on the last days of holiday :p Enjoy! And I always wait for your comments, suggestions, or critics 🙂
5) Plastic ruler
1) Put some salt and some pepper onto the plate. Stir it around.
2) Rub the plastic ruler back and forth on the top of your head.
3) Bring the plastic ruler closer to the mixture of salt and pepper on the plate.
4) Observe what happen next.
-> The pepper particle is attracted to the ruler. Meanwhile, the salt particle stays on the plate.
When we rub the plastic ruler to our hair, the ruler gains more electron from our hair. It becomes negatively charged. Both the salt and the pepper are positively charged. According to the principle of charge interaction, both of them (salt and pepper) should have attracted to the ruler (because they are opposite charges with the ruler). But, the pepper particle is lighter than the salt particle. The salt particle is heavier, so it isn’t as easy as the pepper particle to be atttracted to the ruler. The ruler attracts the pepper easily while the salt stays at its place.