Potential Related to Electric Field?

AI Thread Summary
A manufacturer claims that a carpet will not exceed 4.9kV of static electricity, prompting a discussion on the charge transfer needed to create this potential difference between a carpet and a shoe, modeled as large sheets of charge. The capacitance of the shoe can be estimated using the formula C = ε₀ * A/d, with suggested dimensions for the shoe area leading to a capacitance of approximately 40 to 50 pF. Using this capacitance, the charge required to achieve a 4.9kV potential difference is calculated to be around 25 x 10^-8 Coulombs. The conversation highlights the challenge of estimating capacitance without specific area measurements. Overall, the discussion emphasizes the relationship between voltage, capacitance, and charge in static electricity scenarios.
mitchellhewer
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A manufacturer claims that a carpet will not generate more than 4.9kV of static electricity. What magnitude of charge would have to be transferred between a carpet and a shoe for there to be a 4.9kV potential difference between the shoe and the carpet. Approximate the shoe and the carpet as large sheets of charge separated by a distance d = 1.0mm. Area is not given in the question. Could someone please explain how to do this question in detail? Thank you in advance.
 
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Q=CV. What's the capacitance of the shoe?
 
There is no area of the shoe given. Apparently, someone has told me that I can solve it in terms of σ, the charge per unit area, not the total charge.
 
And there is no capaicitance given either.
 
Why 4.9kV - sounds oddly precise.

The only thing I can suggest is that you need to at least estimate the size of a shoe, then treat it as a simple parallel plate capacitor.
Then C = 8.854×10−12* A/d

Each plate area A - say .1 * .05 gives C= 4.4 x 10-11.

Sounds about right - 40 to 50pF

So Q = 4900 * 50pF = 25 x 10-8 Coulombs.

You want electrons with that?
 
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