Why Are Rubbed Plastic Pieces Attracted to Each Other?

[fiziksfun]

1. I'm doing a lab involving electromagnetic force. In the lab I stroked two pieces of clear plastic that were lying on a table. When I held the two pieces of plastic up in the air near each other, they were attracted to one another.

I don't understand why at all? Any ideas?!
Did I give the plastic a charge when I rubbed it ?! If they're attracted doesn't that mean they have opposite charges ?! Help!

 

[Kurdt]

The plastic will have built up a static charge yes. Since they were attracted the charges will be opposite.

 

[ogb p]

The phenomenon you observed is a result of the electromagnetic force, which is one of the fundamental forces of nature. This force is responsible for the interaction between charged particles, such as the electrons in the plastic pieces. When you rubbed the plastic, you most likely transferred some electrons from one piece to the other, giving them a net charge. Objects with opposite charges are attracted to each other, which is why the plastic pieces were drawn towards each other when held near. This is known as the electrostatic force, a type of electromagnetic force. Keep in mind that the strength of this force depends on the distance between the two objects and the amount of charge they possess. I hope this helps clarify the concept of electromagnetic force for you.