A 10.0 gram piece of styrofoam carries a net charge of -0.700[tex]\mu[/tex]C and floats above the center of a large horizontal sheet of plastic that has a uniform charge density on its surface. What is the charge per unit area on the plastic sheet?(adsbygoogle = window.adsbygoogle || []).push({});

2. Relevant equations

[tex]\Phi[/tex] = E[tex]\int[/tex]dA = [tex]\frac{q}{\epsilon}[/tex]

3. The attempt at a solution

I wasn't even sure how to start this problem. The fact that mass is given threw me off and I can't see how it would be used in the problem. I thought that possibly it could be used to find the electric force between the two objects since it must overcome the downward gravitational pull on the styrofoam (right?). From there, I used the equation that states F=qE to get that the magnitude of the electric field of the styrofoam is -1.4E5. Still, I have no idea how to find the charge per unit area of the plastic sheet and don't think my approach is anywhere near correct. Can someone please help me?

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# Homework Help: Gauss's Law to Symmetric Charge Distribution

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