Calculating Electron Potential Energy in a Thunderstorm

In summary, during a thunderstorm, there is an electric potential difference of 4.0 x 10^8 V between a cloud and the ground. This leads to a change in an electron's electric potential energy as it moves from the ground to the cloud. The electric potential is described as voltage and is measured in units of electron volts. The force on electrons in the ground causes them to move to the cloud, resulting in a loss of potential energy.
  • #1
metalmagik
131
0
During a particular thunderstorm, the electric potential difference between a cloud and the ground is Vcloud - Vground = 4.0 x 10^8 V, with the cloud being at the higher potential. What is the change in an electron's electric potential energy when the electron moves from the ground to the cloud?

I have no idea how to do this problem. Haven't done electric circuits in a year. Any tips or suggestions or formulas to start me off? I was thinking since the number given is change in Potential...can we use a potential formula like V = kq/r? I am not sure what applies here. Any tips at all would be really appreciated, thank you.
 
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  • #2
Hint -- I believe that electron movement was probably part of a lightning strike...

Also, do you know what units are used with electrical potential?
 
  • #3
Hint -- I believe that electron movement was probably part of a lightning strike...

I don't get that hint, I'm probably really dumb since it's probably sarcasm haha. Does that mean it's equal to the potential difference given?


electrical potential = voltage?
 
  • #4
Not dumb at all. The cloud is described at being at the higher positive potential, and that means that the electric field is pointing from the clouds to the earth. F=qE, so the force on a positive charge would be from the clouds down, but the physical situation is that there is a force on electrons in the ground, and they all arc over at once to generate the lightning bolt. So yes, at least from my perspective, the electrons *lost* the potential energy associated with the initial voltage difference. Does that make sense?
 
  • #5
It makes a little sense...let me see if I can understand...you're saying the electrons that go from the clouds to the ground, lose the given potential difference? Since they are afterall going from higher to lower. But now that it's the other way...is it simply gaining this change?
 
  • #6
No, the electrons are starting on the ground and zinging up to the cloud. The - charge of the electrons is attracted by the + charge (lack of electrons) in the cloud. Remember that electron flow is always in the opposite direction of the imaginary "positive current", so electrons are accelerated in the opposite direction of the electric field vector.
 
  • #7
AHI understand that now...but what just came to mind is... Work = qV. I used this formula and got the right answer for this problem.
 
  • #8
metalmagik said:
AHI understand that now...but what just came to mind is... Work = qV. I used this formula and got the right answer for this problem.

Yes, one of the units for energy is electron volts. Quiz question -- 1J = how many eV?
 
  • #9
6.25 x 10^18 eV? :-)
 

1. What is electric circuit potential?

Electric circuit potential, also known as voltage, is the measure of the potential energy that exists between two points in an electric circuit. It is the force that drives the flow of electric charge.

2. How is electric circuit potential measured?

Electric circuit potential is measured in units called volts (V) using a device called a voltmeter. The voltmeter is connected across the two points in the circuit and measures the difference in potential energy between them.

3. What factors affect electric circuit potential?

The factors that affect electric circuit potential are the amount of charge present, the distance between the two points, and the type of material in between the two points. Additionally, the type and arrangement of components in the circuit can also affect the potential difference.

4. How does electric circuit potential impact the flow of current?

The difference in electric circuit potential between two points determines the direction and rate of flow of electric current. Higher potential difference results in a higher flow of current, while lower potential difference results in a lower flow of current.

5. Can electric circuit potential be negative?

Yes, electric circuit potential can be negative. This indicates that the flow of current is in the opposite direction to the flow of positive charge. It can also indicate a decrease in potential energy between two points in the circuit.

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