Electrical Potential Energy Problem

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SUMMARY

The discussion centers on calculating the distance between two metal spheres based on their electrical potential energy after transferring 1013 electrons. The charge of the first sphere is calculated as 1.6 x 10-6 Coulombs, while the second sphere remains uncharged initially. The correct formula used is the Coulomb's law equation, incorporating the Coulomb constant (8.99 x 109 N m2/C2) to find the distance, which the book states is 0.32 meters. The key takeaway is to ensure the conversion of electrons to Coulombs is performed correctly for both spheres.

PREREQUISITES
  • Understanding of Coulomb's law and electrical potential energy
  • Familiarity with charge conversion from electrons to Coulombs
  • Basic knowledge of electrostatics and metal sphere behavior
  • Ability to manipulate scientific notation in calculations
NEXT STEPS
  • Study Coulomb's law in detail, focusing on its applications in electrostatics
  • Learn about electrical potential energy and its calculations in different configurations
  • Explore charge distribution in conductive materials and its effects
  • Practice problems involving multiple charged objects and their interactions
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in electrostatics, particularly those tackling problems related to electrical potential energy and charge interactions between conductive spheres.

Embermage
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Hello,

I've been trying and trying to do this problem for quite a while now, and I can't seem to get an answer which agrees with the book.

In a charging process, 10^13 electrons are removed from a metal sphere and placed on a second sphere that is initially uncharged. Then the electrical potential energy associated with the two spheres is found to be 7.2x10^-2 Joules. What is the distance between the two spheres?

I figured that one metal sphere would then end up with a charge of 10^13 electrons (so I multiplied that by 1.60x10^-19 to get the charge of all the electrons in the sphere). But there is no charge given for the second sphere! I was using the equation:

(q1*q1/r)Coloumb Constant (8.99*10^9) = Energy

Nothing seems to work. Even using the same value for q1 and q1 doesn't produce the correct answer, which the book feels is 0.32 meters.

I'm stuck... thanks so much for any help!
 
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Try making the assumption that the sphere that lost the electrons was initially neutral in charge. Don't forget to convert electrons to coloumbs twice, once for each charge!

cookiemonster
 
Thank you very much... it worked like a charm.
 

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