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Brennen berkley
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Homework Statement
Consider two metal spheres, sphere 1 having radius R1 = 20 cm, and sphere 2 having a radius R2 = 10 cm. The two are rather close to one another, separated by a center-to-center distance of only 80 cm. Suppose now that they are connected to each other by a thin wire that is broken open in the middle by a switch. Initially sphere 1 is charged to 5 nC, and sphere 2 is neutral. When the switch is closed, charge moves spontaneously from sphere 1 to sphere 2 un- til equilibrium is reached. (For simplicity, assume that the charge is uniformly distributed on their surfaces, neglecting the fact that the two spheres tend to polarize one another, and assume that very little charge remains on the con- necting wire because it is so thin.) What is the maximum work (in Joules) that could be extracted from the discharge process if one were so inclined?
Homework Equations
Q1/R1 = Q2/R2
W = Q2/2C
The Attempt at a Solution
I calculated how much charge moved from sphere 1 to sphere 2:
Q1/R1 = Q2/R2
Q2 = 10(5 - Q2)/20
Q2 = 1.66 nC
I don't know how to convert that charge into work done, since it isn't a capacitor or a uniform electric field. If I calculate the voltage between the two spheres I could treat them as I would a capacitor, but I'm not sure how to do that. Help please?