Electrical Potential Energy Problem

In summary, the conversation is about a problem involving the transfer of 10^13 electrons between two metal spheres. The electrical potential energy associated with the two spheres is 7.2x10^-2 Joules and the distance between the two spheres needs to be calculated. The person is struggling to find the correct answer using the given equation and has tried various approaches. However, after making the assumption that the initial charge of the first sphere was neutral, they were able to solve the problem successfully.
  • #1
Embermage
7
0
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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  • #2
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
 
  • #3
Thank you very much... it worked like a charm.
 

What is electrical potential energy?

Electrical potential energy is the energy that a charged particle possesses due to its position in an electric field. It is a measure of the work required to move the particle against the electric field.

How is electrical potential energy calculated?

Electrical potential energy is calculated using the formula U = qV, where U is the potential energy, q is the charge of the particle, and V is the electric potential.

What is the difference between electrical potential energy and electric potential?

Electrical potential energy is a measure of the energy that a charged particle possesses, while electric potential is the potential energy per unit charge. In other words, electric potential is a measure of the electric potential energy per unit charge at a specific point in an electric field.

How does distance affect electrical potential energy?

The farther a charged particle is from a source of electric potential, the lower its potential energy will be. This is because as the distance increases, the force of the electric field on the particle decreases, leading to a decrease in potential energy.

What are some real-life applications of electrical potential energy?

Electrical potential energy has many important applications, such as in the functioning of batteries, generators, and electric motors. It also plays a crucial role in the behavior of charged particles in circuits and in the operation of electronic devices.

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