Charging by contact Friction, Conduction

Learning goals We are learning to charge objects by conduction. We are learning to use two types of electroscopes. We are identifying conductors and insulators.

Charging by conduction charging an object by contact with a charged object electrons transfer from a charged object into a neutral object neutral object gains same type of charge as object that touched it

grounding symbol for grounding removing a charge from an object by connecting it with a conductor to the ground electrons flow into the Earth so the object becomes neutral since the Earth is so large, adding these electrons does not change it symbol for grounding

Electroscopes

Electroscope a device that detects the presence of charge there are two types Metal leaf Pith ball

consists of a metal sphere, rod, and leaves (1) Metal Leaf consists of a metal sphere, rod, and leaves sphere rod leaves

Metal Leaf cont’d… - when the leaves become charged they repel this happens when a charged object either touches or comes near the electroscope - +

How it Works when a charged object is brought near or touches the ball of the electroscope, the electroscope becomes charged because the electroscope is a conductor the charge will spread all over when the leaves become charged they repel

Negatively Charged Object Positively Charged Object (2) Pith Ball a ball of pith hanging on a string can test for presence of charge and type of charge by: bringing object close to neutral pith ball if the object is charged the pith ball will be attracted to it   Negatively Charged Object +   Positively Charged Object - - - - - - - + - - + + + - - - + - + - - +

Learning goals We are learning to charge objects by conduction. We are learning to use two types of electroscopes. We are identifying conductors and insulators.

Lab Testing for Conductors and Insulators