# Essay Question on Potential Electric Energy

1. Apr 10, 2007

### jkola07

If the electric field is 0, then is the electric potential 0?
If the Electric pottential 0 then is the electric field 0?
Explain why or why not.

.. I rather say my idea on this topic, this my first post I am rather shy...

2. Apr 10, 2007

### jkola07

I belive when the electrical potential is 0 that dose not necessary mean that the electrical field is 0 but if the electrical field is 0 than the electrical potential is 0, its just common sense to me I do not know how to explain can I get some help.

3. Apr 10, 2007

### jkola07

is it because electirical potential is directly related to the electrical field...and electrical field can be in full motion meaning in full kinetic electric energy causeing there to be 0 potential??? Please help am I on the right track>

4. Apr 10, 2007

### denverdoc

First, there is not a man or woman on this forum who has not committed enormous blunders of reasoning. I myself recognize at least 3 in the past week alone, and friends suggest its closer to 30. My daughter would estimate it at 300,000 in one of her more sour moods, in other words, every breath I take is a mistake.

There is one basic rule here at the Physics Forum that we adhere to. You are required to post at least some thoughts on the problem with which you would like help. It can be very simple, such as a definition of electric field and electric potential. You have already given the issue some consideration obviously. Often many seeking help have the additional disadvantage of trying to learn physics without much help from teachers or access to materials in their native language. I'm US born and have a good command of english and a better command of math, and it is still so, so hard at times.

So as a way of getting your feet wet, just add a couple of thoughts about what potential is. Maybe consider what you know about gravity if you have studied this as there are many anologies.

Welcome. We are here to help.

Last edited: Apr 10, 2007
5. Apr 10, 2007

### denverdoc

Excellent, somewhere between my post and your first you added much more.

These are very difficult questions you ask. I very much agree that one can be in an electric field and have no potential. The simple example would be a particle with no charge. Or in a situation where more than one field is present and exerting force on a particle such that net potential is zero?

6. Apr 10, 2007

### jkola07

oh thanks...the Electrical potential energy is Kc(q^2/d) electrical field is Kc(q/d^2).. um in regard to gravitiy I suppose gravitational force and eletrical field are related....when it it comes to Gravational potential energy there is a point where it is zero is that when kinetic energy is the greatest?.. So would I compare Ep to Ef with anaolgy of a ball that is thrown up and has at a point 0 potential energy but still has force acting upon it... I'm I anywhere near the right track?

7. Apr 10, 2007

### jkola07

oh thanks I did not see the previous post.... thanks

8. Apr 10, 2007

### jkola07

Well can other force other than electrical alter electric potential energy?

9. Apr 10, 2007

### denverdoc

you're thinking, and thats all that matters. Sometimes people visit PF just because they have better things to do and want homework to be done or checked for them.

Lets look at the gravity situation, you throw a ball up and it stops at some point, thats when the potential energy is greatest. Then during ascent is exchanges porential for kinetic energy. More what I had in mind was a particle between the moon and earth where the forces exerted exactly offset. With gravity, there is always attractive force.The conditions for electrical potential energy are wider given that it can be both attractive and repulsive. I don't wish to make this seem too complicated for now.

10. Apr 11, 2007

### jkola07

If the electrical field is 0 then the electrical potential can be 0 this can be easily illustrated in when a particle has no charge in a electrical field. However when the electrical potentail is 0 that does not mean electrical field is 0 because there can be vaule to a electric field when Electrical potential is 0 an example of this is when more than on field is present exerting force on a partcle resulting the net potential energy to be 0

sound good?

11. Apr 11, 2007

### christianjb

Uhhh,

in 1D

E(x)=-d phi(x) / dx

where E(x) is the field, phi(x) is the electric potential.

if phi(x)=C (a constant, could be 0, doesn't have to be)

E(x)=0