**Electric potential energy of the system of three charges**
1:
The electric potential energy of two point charges approaches zero as the two point charges move farther away from each other.
If the three point charges (**two positive, one negative**) lie at the vertices of an equilateral triangle, the electric potential energy of the system of three charges is...
Answer: negative.
2:
The electric potential energy of two point charges approaches zero as the two point charges move farther away from each other.
If the three point charges (**one positive, two negative**) lie at the vertices of an equilateral triangle, the electric potential energy of the system of three charges is...
Answer: negative.
Why would this be the case?
Equation for electric potential energy is, U = K( SUM[qi/ri] )
=> U = (q1/r1) + (q2/r2) + (q3/r3) ).
By this equation, I understand that the second question would be negative by U = (+q1/r1) + (-q2/r2) + (-q3/r3) ) = -q2/r2.
But Looking back at the first question, this doesn't hold.
Applying the first line of the question, will leave negative(question1) and positive(question2), so this also doesn't work.
What am I missing?
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Last edited by johnwill8258; Sep 21st 2016 at 08:00 PM.
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