Additional Physics Topic 1

Static electricity is due to the build up of the electrical charge. It is called static as the charge is unable to flow. The build up electric charge can cause dangerous sparks. Sometimes after walking on a carpet and then touching a metal object such as a door knob, you might get a small shock. This is called static electricity. 

Static electricity is due to electric charge that builds up on the surface of an insulator, such as a plastic comb. The charge that has built cannot easily flow away from the insulator which is why it is called static electricity. 

Static charge can build up when two insulating materials are rubbed together such as a plastic comb moving through hair. Friction between the materials cause electrons to be transferred from one material to another. One material will end up with more electrons so it has an overall negative charge and one material will end up with fewer electrons so it has an overall positive charge. 

Acetate: If an acetate rod is rubbed with a cloth, electrons move from the rod to the cloth. The acetate rod loses electrons to the cloth and so ends up with an overall positive charge.

Polythene: If a polythene rod is rubbed with a cloth, the electrons move from the cloth to the rod. The polythene rod gains electrons from the cloth so ends up with a negative charge.

Only electrons can move, not proton. Two opposite electric charge are attracted to each other and the two things with the same electric charge will repel from each other. The forces get weaker the further apart the two things are.

Clothing Crackles 

If synthetic clothes are rubbed against each other so for example in the tumble dryer or over your head, the electrons get transferred leaving a static charge on both of the object involved. This leads to the attraction between the static charges and little sparks as the charge rearrange themselve. 

Car Shocks

Static charge builds up between the clothes and the synthetic car seat so the friction between them causes the electrons to be transferred, therefore an static charge is build up on the person and when they touch the metal door the charge flows and can give you an electric shock. However, some cars have conducting strips which discharges the charge safely. 

Shocks from door handle

When a person walks along a nylon carpet wearing insulating soles, the electrons will be transfered between the two objects and charge will build up on the persons body. Therefore when you…