Finding Zero Potential between Two Charges: Using the V=kQ/d Equation

In summary, this user is trying to find the potential energy of two charges by using the equation V=kQ/d, but they appear to be confused about what potential and potential energy are.
  • #1
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Homework Statement


I'm supposed to look for where the potential is zero on the same line where two different charges lie.
I'm given the values of the two charges and the distance between them, I have to find where the potential is zero.

Homework Equations


The Attempt at a Solution


I'm thinking about using the equation
W = kQ1Q2 ( 1/d1 - 1/d2)
I tried plugging in for Q1 and Q2 and the given distance into either d1 or d2. Where's my mistake? Or I'm supposed to use another equation? Also, is the W the same as the required "potential?"
 
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  • #2
Potential energy(and potential!) and work are not the same thing, but they're related in these cases when dealing with electric fields(and also gravitational fields)

More importantly you appear to have also confused potential and potential energy

Do you know the equation for potential? You can write an equation for both charges, add them and set them equal to 0 to solve for the required position

As far as the difference between PE and work in a conservative force field(like gravity or electric fields)if you change something's potential energy you have DONE work to it against its respective force field

The potential function is technically potential energy per charge in an electric field, which is a little abstract, and it may not seem obvious why it's useful, but look at this problem. You found where the potential is 0, so you know F=-grad(potential) so you've actually found where the force cancels out between the two of them, without having to screw around with the force equation(and also from that equation you know wherever the potential is constant the force also equals 0
 
Last edited:
  • #3
Thank you for clearing that up. I'm using the V=kQ/d equation now. I'm actually working on the same problem as the one another user has asked about. But I got it now, thanks.
 

Related to Finding Zero Potential between Two Charges: Using the V=kQ/d Equation

1. What is potential energy?

Potential energy is the stored energy an object has due to its position or state. It is the energy that an object has the potential to convert into other forms of energy, such as kinetic energy.

2. How is potential energy related to work?

Potential energy is related to work through the principle of conservation of energy. When an object's potential energy is converted into kinetic energy, work is being done. This work is equal to the change in potential energy.

3. What are some examples of potential energy?

Some examples of potential energy include a stretched spring, a raised weight, a compressed gas, and a charged battery. In each of these situations, the object has the potential to do work when released or used.

4. Can potential energy be negative?

Yes, potential energy can be negative. This is often the case when the reference point for potential energy is chosen to be at a lower level than the object. For example, the potential energy of an object at the bottom of a hill would be negative compared to the potential energy at the top of the hill.

5. How is potential energy quantified?

Potential energy is quantified using the equation PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height of the object above the reference point. The unit for potential energy is joules (J).

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