Pysics - Topic 1

•  Static electricity is about charges which are not free to move causing them to build up resulting to a shock/sparkonce they finally move.

• A substance that gains electrons becomes negativelycharged.
• A substance that loses electrons becomes positively charged.

• If charges are the same they repel
• If charges are opposite they attract
• if One is charged and one is not they attract

Example: When an acetate rod is rubbed with a duster, electrons are transferred from the rod onto the duster, making the rod positively charged. Play the animation below to see how this happens.

• Build of static electricity is caused by friction.
• When two insulating materials are rubbed together, electrons are scraped off one and dumped on the other. One will have a positive charge and the other will have a negative charge.

How can you tell if an insulator is charged? Examples could be:

• If a plastic rod is rubbed with a duster, it attracts small pieces of paper
• When a balloon is rubbed against a jumper it can stick to a wall. Some dusters are designed to become charged so that they attract dust.

Examples: When synthetic clothes are dragged other each other (e.g. tumble drier) electrons gets scraped off, leaving static charges on both parts. This leads to the attraction (they stick together) and little sparks as the charges rearrange themselves.

Static charge can also build up between your clothes and a synthetic car seat - the friction between the two causes electros to be scraped…