Comparing 100J and -100J of Electric Potential Energy

In summary, the question is asking whether 100 J of electric potential energy is greater than -100 J of electric potential energy. The answer is that they have the same magnitude, but the sign indicates the work needed to bring a +1C charge to those two potentials. Positive work is needed to bring +1C to the +110J point (pushing up a hill), while negative work is done to bring the +1C charge to the -100J point (sliding down to a valley). Therefore, one configuration has 200 J less electrical potential energy than the other. The context and intended answer may vary depending on the specific scenario.
  • #1
rpthomps
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Is the 100 J of electric potential energy actually greater than -100 J of electric potential energy?
 
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  • #2
They have the same magnitude but the sign is the indication of the work done (energy needed) to bring a +1C of charge from an infinite distance to points with those two potentials. The definition is that Positive work is needed to bring +1C to the +110J point (pushing up a hill) but negative work is done (i.e. energy is got out) then the +1C is brought to the -100J point (sliding down to a valley).
 
  • #3
rpthomps said:
Is the 100 J of electric potential energy actually greater than -100 J of electric potential energy?
Given the way the question is phrased and the units that are used, I would interpret it to be about the potential energy of two configurations of the same system. One with a potential energy 100 J more than an arbitrary reference potential and one with 100 J less than the arbitrary reference.

Clearly, one has 200 J less electrical potential energy than the other.
 
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  • #4
jbriggs444 said:
Given the way the question is phrased and the units that are used, I would interpret it to be about the potential energy of two configurations of the same system. One with a potential energy 100 J more than an arbitrary reference potential and one with 100 J less than the arbitrary reference.
Clearly, one has 200 J less electrical potential energy than the other.
Sounds fair and I can't find fault with that. The question could either require a totally theoretical answer or something practical. We would need the OP to give us a bit of help with the context. What does he actually want to know and why?
Can @rpthomps help us to help him more, please?
 
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  • #5
sophiecentaur said:
The question could either require a totally theoretical answer or something practical.
Or it might have the syntax of a question but be devoid of semantics.
 
  • #6
Thanks guys for the response! The question, was answered, as intended by @sophiecentaur but @jbriggs444 brought up another way of thinking about it.
 

Related to Comparing 100J and -100J of Electric Potential Energy

1. What is electric potential energy?

Electric potential energy is a form of potential energy that results from the interaction between electric charges. It is the amount of work that can be done by an electric force as a result of the position or configuration of the charges.

2. What is the significance of comparing 100J and -100J of electric potential energy?

The sign of the electric potential energy indicates the direction of the electric force. A positive value indicates that the charges are repelling each other, while a negative value indicates that the charges are attracting each other. Comparing 100J and -100J of electric potential energy allows us to determine the direction of the electric force between two charges.

3. Can electric potential energy be created or destroyed?

No, electric potential energy cannot be created or destroyed. It can only be converted into other forms of energy, such as kinetic energy or thermal energy.

4. How is electric potential energy measured?

Electric potential energy is measured in joules (J), which is the standard unit of energy. It can also be measured in electron-volts (eV), which is a smaller unit of energy commonly used in atomic and subatomic physics.

5. How does the distance between charges affect electric potential energy?

The electric potential energy between two charges is directly proportional to the magnitude of the charges and inversely proportional to the distance between them. This means that as the distance between charges increases, the electric potential energy decreases, and vice versa.

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