Metal sphere left by alien civilization

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SUMMARY

The discussion centers on calculating the charge of a metal sphere left by an alien civilization based on voltage readings at two distances. The voltage detected by a probe is 110.0 V at 1000 m and 10.0 V at 100.0 m. The user attempts to apply the equation V = (kq)/r to find the charge (q) but encounters inconsistencies in the results. The correct approach involves using the inverse relationship between voltage and distance to derive a consistent value for charge.

PREREQUISITES
  • Understanding of electrostatics, specifically voltage and charge relationships.
  • Familiarity with Coulomb's law and the constant k (Coulomb's constant).
  • Basic algebra skills for solving equations.
  • Knowledge of the concept of electric potential and its measurement.
NEXT STEPS
  • Review the derivation of the equation V = (kq)/r in electrostatics.
  • Learn about the implications of distance on electric potential and charge calculations.
  • Study the concept of electric fields and how they relate to voltage measurements.
  • Explore practical applications of electrostatics in real-world scenarios.
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding electrostatics and charge calculations in theoretical scenarios.

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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