Understanding Charge in Physics: Solving a Problem with Plastic Wrap

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The discussion revolves around a physics problem involving static electricity and charge interaction. The individual is trying to understand why a positively charged piece of plastic wrap (+3*10^-7 C) is sticking to a negatively charged roll of plastic wrap. It is established that the roll must have a negative charge to attract the positively charged wrap, which is a fundamental principle of electrostatics. The interaction highlights the concept that opposite charges attract, explaining the difficulty Jim faces in removing the wrap. Understanding these charge interactions is crucial in solving similar physics problems.
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Hi, sorry if this is in the wrong forum.

I have a physics problem I do not understand:

Jim is removing a piece of plastic wrap from a large roll. However, he is finding that this is difficult because the piece of plastic wrap keeps trying to stick to the roll. If the charge on the piece of plastic wrap is +3*10^-7 C, what is the charge on the roll of plastic wrap? How do you know this?

I know the plastic wrap roll is negative charge, and that's about it.

Help!
 
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