Presentation on theme: "Charging By Friction When two objects are rubbed together, the molecules are close enough together that the electrons from one substance can move onto."— Presentation transcript:
1Charging By FrictionWhen two objects are rubbed together, the molecules are close enough together that the electrons from one substance can move onto the other substance.
2The substance that gains extra electrons becomes negatively charged, while the substance with fewer electrons becomes positively charged.The more rubbing, the more transfer, the greater the charge.
3The Electrostatic Series As previously discussed, some objects hold their electrons tighter than others.The electrostatic series ranks objects by how easily they let go of e- during friction.
4Substances that let go easily are on top and become positively charged. Substances on the bottom hold tight and take on a negative charge.The further the substances are apart, the more charge that it produced.
5+AcetateGlassWoolFur or hairSilkAluminiumCottonParaffin waxPlasticRubberGold-
6ExampleWhen clothes are put in a dryer without fabric softener, they rub against each other and become charged.Which item would take on which charge if:
7- + Cotton socks are dried with a wool sweater? b) A wool sock is dried with a silk shirt?
8When you comb your hair with a plastic comb, your hair becomes statically charged.
10What could you use to make a comb that would produce less charge? Hair + AluminiumComb - Acetate
11Charging By ContactElectric charge can be transferred between objects just by touching them together.Charging by conduction occurs when a charged object touches a neutral object.
12A few electrons move from one object to the other (electrons try to move where they are needed). As a result, both objects end up with the same charge.
13Charging By Introduction Neutral objects are attracted to charged objects.In fact, a charged object can induce a charge in another object.
14The neutral object never actually gains or loses any electrons. When the charged object is brought close, the electrons move slightly in the uncharged object.
15So if a positive object in brought near, the electrons are attracted and move closer. If the charge is negative, the electrons are repelled and move away.
16Discharging An ObjectIf you connect an electrical device or something with a charge to the earth or the ground, then the extra charges get transferred into the Earth.Since the Earth is so large, it can accept a lot of electrons without having much effect.This is called grounding an object.