Electroscope activity  Rub plate and pipe together  Bring pipe near (but don’t touch) electroscope 1.What happens?  Bring plate near (but don’t touch) electroscope 2.What happens? 3.Does you observe any difference between plate and pipe?

Drawing charge  The plate is now positively (+) charged  What is the charge on the pipe (+ or -)? 4.Draw a plate and a pipe on your paper with the appropriate positive and negative charges  Can you bring both plate and pipe to the electroscope so that the tinsel doesn’t respond? 5.Why do you think it worked?

Modeling your electroscope  Bring the charged plate near your electroscope  Model what you see with your paper model  What kind of charge is causing the tinsel to repel?  Draw your model

Charge by Induction 1  With the plate near the electroscope, touch the can with your finger. What happens to the tinsel? What does this tell you about the charge on the tinsel?  Model what you see  Draw your model

Charge by Induction 2  Take your finger off the can and then remove the plate. What do you observe?  Model what you see.  Draw the model  You now have a charged electroscope. What is the charge (+ or -) on it?

Testing a negatively charged object with a negatively charged electroscope  Predict what would happen if you slowly brought a negatively charged object near your negatively charged electroscope  Model it  Draw it  Try it

 Predict what would happen if you slowly brought a positively charged object near your negatively charged electroscope  Model it  Draw it  Try it Testing a positively charged object with a negatively charged electroscope

Can a neutral electroscope be use to determine the sign (+ or - ) on a charged object?

Can you charge your electroscope positively?  Draw each step in the process Determine the charge on a vinyl record rubbed with fur