Determine the net charge of sphere C

isukatphysics69

1. Homework Statement
Consider three identical metal spheres: Sphere A carries a charge of -9q, Sphere B carries a charge of +3q, and Sphere C is neutral.

Spheres A and B are touched together and then separated.

Next, Sphere C is touched to Sphere A and then separated from it.

Finally, Sphere C is touched to Sphere B and then separated from it.

What is the final net charge on Sphere C? Express your answer with the appropriate +/- sign and use q as the unit.

2. Homework Equations
None

3. The Attempt at a Solution
When sphere A and B touch, they will transfer charge to each other, and since sphere C is neutral it has no effect on this transfer. A and B are now net negative because of the dominant -9 net charge on sphere A

Sphere A & B are now -3q each

now sphere A touches sphere C and B is net negative polorizing the transfer process, so sphere A at -3q touching neutral sphere C with the polorizing effect of sphere B is going to make it so that sphere C becomes more negative and sphere A becomes more positive, they will not neutralize, correct? now I am confused how I should put a number on the spheres after this process

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kuruman

Homework Helper
Gold Member
I think the problem wants you to consider sphere B far away when A touches C so that it does not influence the charge transfer process. What happens when a sphere with -3q charge touches a sphere with zero charge?

• isukatphysics69

isukatphysics69

I think the problem wants you to consider sphere B far away when A touches C so that it does not influence the charge transfer process. What happens when a sphere with -3q charge touches a sphere with zero charge?
Hey, I actually just got it on the first try which almost never happens im so happy lol the answer is -2.25q. I also have no idea what unit a q is

"Determine the net charge of sphere C"

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