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knowlewj01
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Homework Statement
A hollow sphere of radius [itex]r_1[/itex] is placed at the centre of a larger hollow sphere of radius [itex]r_2[/itex].
Both spheres have a uniformly distributed total charge of +q
Find the preassure [itex]p(r_2 , q)[/itex] which acts on the outer sphere.
Homework Equations
[itex]\oint\textbf{E.n}dS = 4\pi k Q[/itex]
[itex]p = \frac{dF}{dA}[/itex]
The Attempt at a Solution
Inside the larger sphere, there is no contribution to electric field from the large sphere, so just consider the electric field at [itex]r_2[/itex] due to the inner sphere:
[itex]E(4\pi r_2^2) = 4\pi k q[/itex]
[itex]E = \frac{kq}{r_2^2}[/itex]
since [itex]F = qE[/itex]
the force acting at [itex]r_2[/itex]:
[itex]F(r_2) = \frac{kq^2}{r_2^2}[/itex]
[itex]p = \frac{F}{A}[/itex]
[itex]p = \frac{kq^2}{4\pi r_2^4}[/itex]
does this look right?
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