ACTIVITY - TEACHING “CHARGING BY CONTACT You are going to explain charging by contact to a partner. Your partner will assess your performance using the rubric provided. You will both have a chance to be the teacher and the assessor. 1) The first teacher will explain (using diagrams and words) what happens when a negatively charged rod is brought up to a neutral object. The charged rod touches the neutral object, is taken away and then brought back to close the object. The other partner will assess their performance and give feedback when they are done. 2) The second teacher will explain (using diagrams and words) what happens when a positively charged rod is brought up to a neutral object. The charged rod touches the neutral object, is taken away and then brought back to close the object. The other partner will assess their performance and give feedback when they are done. SWITCH

CHARGING BY INDUCTION neutral pith negative balloon Replace string with rigid steel rod electrons repelled Induced Charge Separation A slight shift in the position of electrons that produces opposite charges on the two sides of the object balloonbrought close to pith

CHARGING BY INDUCTION What would happen if a wire was attached to the pith ball and connected to the ground? The Law of Electric Charges tells us that like charges want to get as far away as possible from each other. Some electrons take the path to the ground through the wire If the wire is removed and the negative balloon taken away, what is the charge on the pith ball? The pith ball is now positively charged END RESULT: The neutral pith takes on a charge that is opposite to the balloon

neutral pith positive acetate CHARGING BY INDUCTION Induced Charge Separation

CHARGING BY INDUCTION What would happen if a wire was attached to the pith ball and connected to the ground? The Law of Electric Charges tells us that opposites attract. Electrons enter the pith from the ground as they are attracted to the positive side of the pith. If the wire is removed and the positive acetate taken away, what is the charge on the pith ball? The pith ball is now negatively charged END RESULT: The neutral pith takes on a charge that is opposite to the acetate CONCLUSION: When a neutral object is charged by induction, it takes on a charge that is OPPOSITE to the charge of the inducing object.

SEATWORK 1.Read pg in textbook - in your notes, draw diagrams and use words to explain lightning - explain how lightning rods work 2. Work on handout - “What is Static Electricity?”

negative ebonite