Metal sphere left by alien civilization

AI Thread Summary
The discussion revolves around calculating the charge on a metal sphere based on voltage readings at two distances. The voltage equation used is V = (kq)/r, where k is the electrostatic constant. The user attempts to solve for charge (q) but finds inconsistent results when applying the formula to both voltage measurements. There is confusion about the correct application of the equation, leading to a request for assistance. The urgency of the homework deadline adds pressure to resolve the issue quickly.
winterwind
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voltage/charge problem

Homework Statement


Imagine a small metal sphere left by some alien civilization is floating in space. A
probe is launched directly at the sphere in order to study it. When the probe is
1000 m from the sphere, it detects a voltage of 110.0 V; and when it’s at 100.0 m
it records 10.0 V. What, if any, is the charge on the sphere?



Homework Equations



I used V = (kq)/r


The Attempt at a Solution



Solve for q to get q = V(r/k). Plug in the values for each situation, and get q. The thing is, I get different values of q for each set of values. I must be using the wrong equation...but I can't figure which equation to use that relates charge and volts.

Thanks!
 
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