Charging By Contact. Neutral objects can becomes charged through direct contact in 2 common methods:

Size: px

Start display at page:

Download "Charging By Contact. Neutral objects can becomes charged through direct contact in 2 common methods:"

Barnaby Pope
6 years ago
Views:

1 Charging by Contact

2 Charging By Contact Neutral objects can becomes charged through direct contact in 2 common methods:

3 1. Charging By Friction When two different materials are rubbed together, electrons from one material are transferred to the other. This is because some materials hold on their electrons more strongly than others.

4 1. Charging By Friction When two different materials are rubbed together, electrons from one material are transferred to the other. This is because some materials hold onto their electrons more strongly than others. For example, when you rub a balloon on your hair, the electrons in your hair are transferred to the rubber in the balloon, because the rubber holds onto electrons more strongly than hair does. Before Rubbing

For example, when you rub a balloon on your hair, the electrons in your hair are transferred to the rubber in the

5 1. Charging By Friction When two different materials are rubbed together, electrons from one material are transferred to the other. This is because some materials hold onto their electrons more strongly than others. For example, when you rub a balloon on your hair, the electrons in your hair are transferred to the rubber in the balloon, because the rubber holds onto electrons more strongly than hair does. The balloon becomes negative. After Rubbing The hair becomes positive.

6 1. Charging By Friction When two different materials are rubbed together, electrons from one material are transferred to the other. This is because some materials hold onto their electrons more strongly than others. For example, when you rub a balloon on your hair, the electrons in your hair are transferred to the rubber in the balloon, because the rubber holds onto electrons more strongly than hair does. What happens when you rub materials that are the same together? NOTHING!

7 2. Charging By Conduction Once an object is charged it can pass that charge onto another object by contact. neutral electroscope Charged balloon makes contact with the electroscope.

8 2. Charging By Conduction Electrons move from balloon to the electroscope. Once an object is charged it can pass that charge onto another object by contact. The charge remains even after the object lose contact. charged electroscope The leaves of the electroscope repel each other. Charged balloon makes contact with the electroscope.

9 2. Charging By Conduction Once an object is charged it can pass that charge onto another object by contact. The charge remains even after the objects lose contact. Electrons move from balloon to the electroscope. charged electroscope The leaves of the electroscope repel each other. The electroscope remains charged after contact.

10 Grounding Charged objects can cause a shock if touched. If electrons are allowed to build up in an object, when they do find a path to the ground so many of them move that they can arc through the air as a spark. To prevent gas pumps from developing a dangerous charge, all parts of the pump are well grounded by conductors (wires), so that electrons always have an easy path to the ground. Walking across the carpet in socks can cause you to become charged. Grounding prevents the build up of charge.

If you have you know that not all of the paint goes where

11 Using static charges Static electricity is actually useful! Who knew! Have you even used a can of spray paint? If you have you know that not all of the paint goes where you want it to. It sprays into the air and onto surrounding objects.

12 Electrostatic paint spray To reduce the amount of paint wasted, electrostatic paint sprayers are used. The paint is given a charge as it leaves the nozzle of the sprayer while the object to be painted is given an opposite charge.

13 ELECTRON AFFINITY The tendency of a substance to hold on to its electrons is called electron affinity. Electrostatic Series: a list of materials arranged in order of their tendency to gain electrons Tend to lose electrons Tend to gain electrons () human hands (dry) glass human hair nylon cat fur silk cotton steel wood amber ebonite plastic wrap Teflon () Table 1: Page 473

EXPERIMENT # 2 ALL CHARGED UP! BUILDING AN ELECTROSCOPE

EXPERIMENT # 2 ALL CHARGED UP! BUILDING AN ELECTROSCOPE VOLUNTEERS, PLEASE. Activity from p. 13 NO HAIR PRODUCTS. Electroscopes test the effects of positive and negative charges Charles Du Fay, you will