Two point charges with electric potential energy?

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SUMMARY

The discussion centers on solving for two point charges given their electric potential energy of -180 microJoules and a total charge of 31 nC, separated by 2.0 cm. The relevant equation used is V = k * q / r, where k is the Coulomb's constant (9 x 10^9 N m²/C²). Participants suggest breaking down the total charge into two individual charges, q1 and q2, and using the relationship between potential energy and charge to find their values. The confusion arises in how to manipulate the equations to isolate the individual charges.

PREREQUISITES
  • Understanding of electric potential energy and its formula.
  • Familiarity with Coulomb's law and the constant k (9 x 10^9 N m²/C²).
  • Basic algebra skills for manipulating equations.
  • Knowledge of charge conservation principles.
NEXT STEPS
  • Learn how to derive individual charges from total charge and potential energy equations.
  • Study the concept of electric potential and its applications in electrostatics.
  • Explore the relationship between electric potential energy and distance in point charge systems.
  • Review problem-solving techniques for electrostatic problems involving multiple charges.
USEFUL FOR

Students studying electrostatics, physics educators, and anyone interested in understanding the principles of electric potential energy and charge interactions.

Netsurfer733
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Homework Statement



"Two point charges 2.0cm apart have an electric potential energy -180 microJoules. The total charge is 31 nC. What are the two charges?"

Homework Equations



V= k * q / r

The Attempt at a Solution



I understand that V = -180 * 10^-6, k = 9*10^9, r = 0.02m, and the TOTAL q=31*10^-9 C...but what does that leave us to solve, in this equation? I know we need to find the total charge of the both of them individually, but I don't know how to break this equation up to do that. Can anyone help me see this through?
 
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Hi netsurfer.
Let [tex]q_{1}[/tex] and [tex]q_{2}[/tex] be the charges you are asked to find.
How do these charges enter in your equation ?
 
Exactly, lol...I mean, I would think maybe if you cut the potential in half then solve for q then q1 and q2 would be equal? But that doesn't seem right at all... I'm a bit confused. How would I go about doing it?
 

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