How Do You Calculate the Electric Potential Difference Between Two Points?

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SUMMARY

The calculation of the electric potential difference between two points, X and Y, is determined using the formula V = delta Ep/Q, where delta Ep is the change in electric potential energy and Q is the charge. In this case, point X is 0.25m from a charge of +4.7E-8 C, and point Y is 0.65m away. The correct calculation yields a potential difference of 1041 V, confirming that the potential of point X with respect to point Y is positive when calculated correctly. The misunderstanding regarding the sign of the potential difference is clarified by stating that V_{xy} = V_{y} - V_{x} results in a positive value.

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  • Understanding of electric potential and potential difference
  • Familiarity with Coulomb's law and electric fields
  • Knowledge of basic algebra and calculator operations
  • Concept of electric potential energy (Ep) and its relation to charge (Q)
NEXT STEPS
  • Study the derivation of the electric potential formula V = delta Ep/Q
  • Learn about Coulomb's law and its application in electric field calculations
  • Explore the concept of electric potential energy and its significance in electrostatics
  • Practice problems involving potential differences between multiple point charges
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Students studying physics, particularly those focusing on electromagnetism, as well as educators and anyone seeking to understand electric potential differences in electrostatic contexts.

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Homework Statement



Point X is 0.25m away from a point charge of +4.7 E -8 C, point Y is 0.65m away. What is the potential of point X with respect to point Y?

Homework Equations


delta Ep=delta Ek
V=delta Ep/Q
delta Ep=QV
Ep=kQQ/d

The Attempt at a Solution



delta Ep = -Ep1
W=QV
W=kQQ(1/d-1/d)
QV=kQQ(1/.25-1/.65)
V=(9E9)(4.7E-8 C)(2.4615)
V=1041 V

I don't get one thing when it says with respect to Y, you put the distance of Y as d2 right? But then wouldn't you get a negative answer when it should be positive?
 
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Fusilli_Jerry89 said:
delta Ep = -Ep1
W=QV
W=kQQ(1/d-1/d)
QV=kQQ(1/.25-1/.65)
V=(9E9)(4.7E-8 C)(2.4615)
V=1041 V
What you have done here is all correct, except the answer. You've just punched the numbers into your calculator wrong.
Fusilli_Jerry89 said:
I don't get one thing when it says with respect to Y, you put the distance of Y as d2 right? But then wouldn't you get a negative answer when it should be positive?
The potential of x wrt to y means exactly what you have done there. In other words calculate the potential difference between points x and y like this; V_{xy} = V_{y}-V_{x}, which would lead to a positive answer.
 

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