Calculating the P.E. of a system

Click For Summary

Discussion Overview

The discussion revolves around calculating the potential energy (P.E.) of a system consisting of three particles, focusing on the distinction between potential energy and potential, and the relevance of the point of observation in these calculations. The scope includes conceptual clarification and technical reasoning related to gravitational potential energy (G.P.E.) and the interactions among the particles.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions why the potential energy of particles due to each other must be considered instead of a simpler method of calculation.
  • Another participant asks for clarification on whether the discussion pertains to gravitational potential energy (G.P.E.) and whether kinetic energy (K.E.) is involved, suggesting that the total energy might be the sum of G.P.E. and K.E.
  • A participant asserts that potential energy is not the same as potential and explains that potential can be calculated at a point without considering interactions among the particles.
  • There is a suggestion that potential energy is applied to the collection of particles rather than a point, which leads to confusion regarding the relevance of the point of observation.
  • One participant expresses uncertainty about the concept of G.P.E. varying from point to point, indicating a need for clarification on this aspect.
  • Another participant states that the potential energy of a collection of particles does not vary from point to point, which is acknowledged by a later reply.

Areas of Agreement / Disagreement

Participants express differing views on the relevance of the point of observation in calculating potential energy, with some asserting that it does not vary with the point of observation while others remain uncertain. There is no consensus on the best approach to calculating potential energy in this context.

Contextual Notes

Participants have not fully resolved the assumptions regarding the definitions of potential energy and potential, nor have they clarified the implications of the point of observation in these calculations.

Hawkingo
Messages
56
Reaction score
2
Let, we want to calculate the P.E(potential energy) of a system containing 3particles p1,p2,p3.the point of observation is P.so now we should add up the P.E at P due to p1,p2,p3 to get the net potential energy of the system,but why we take the P.E of particles due to each other into count instead of the previous method.I can't figure it out.
 
Physics news on Phys.org
It would help us all if you could post much more information about the situation you are working with...
  • PE = GPE or does it include other types of PE?
  • If GPE, are you able to assume that the total energy = the sum of the particles' GPE + KE?
  • If GPE, is all of the mass in the three particles?
  • If so, what are the relative masses of your point particles?
  • And what software are you wanting to simulate this problem with?
 
berkeman said:
It would help us all if you could post much more information about the situation you are working with...
  • PE = GPE or does it include other types of PE?
  • If GPE, are you able to assume that the total energy = the sum of the particles' GPE + KE?
  • If GPE, is all of the mass in the three particles?
  • If so, what are the relative masses of your point particles?
  • And what software are you wanting to simulate this problem with?
Yes ,I am talking about the GPE and here K.E is 0 and the mass of the system is in the 3 particles.but the system and point of observation both are stationary so I think their masses are absolute and I am not using any simulation software I am just doing with pen and paper.
 
Hawkingo said:
Let, we want to calculate the P.E(potential energy) of a system containing 3particles p1,p2,p3.the point of observation is P.so now we should add up the P.E at P due to p1,p2,p3 to get the net potential energy of the system,but why we take the P.E of particles due to each other into count instead of the previous method.I can't figure it out.

Potential energy is not the same thing as potential.

You can calculate the potential at point P, and it doesn't involve interactions between ##p_1##, ##p_2##, and ##p_3##.

On the other hand, you can calculate the potential energy of ##p_1##, ##p_2##, and ##p_3##. This does involve the interactions between ##p_1##, ##p_2##, and ##p_3##. The point P is not relevant here. It makes no sense to speak of the potential energy at P. The potential energy is not something that you assign to a point. It's something you apply to the collection ##p_1##, ##p_2##, and ##p_3##.
 
  • Like
Likes   Reactions: nasu
Mister T said:
Potential energy is not the same thing as potential.

You can calculate the potential at point P, and it doesn't involve interactions between ##p_1##, ##p_2##, and ##p_3##.

On the other hand, you can calculate the potential energy of ##p_1##, ##p_2##, and ##p_3##. This does involve the interactions between ##p_1##, ##p_2##, and ##p_3##. The point P is not relevant here. It makes no sense to speak of the potential energy at P. The potential energy is not something that you assign to a point. It's something you apply to the collection ##p_1##, ##p_2##, and ##p_3##.
Don't get me wrong,I want to ask that for example we want to calculate the center of mass of a system and that value is applied to that system because when we measure the mass of the system it appears to be concentrated at the center of mass but in case of G.P.E of a system when we have to measure it we have to observe it by a point of observation and that value varies from point to point.I know I have some misconception but I can't figure it out so I need help.
 
Hawkingo said:
in case of G.P.E of a system when we have to measure it we have to observe it by a point of observation and that value varies from point to point.I know I have some misconception but I can't figure it out so I need help.

The potential energy of a collection of particles does not vary from point to point.
 
  • Like
Likes   Reactions: cianfa72, berkeman and Hawkingo
Mister T said:
The potential energy of a collection of particles does not vary from point to point.
Got it, thanks
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 6 ·
Replies
6
Views
11K
  • · Replies 7 ·
Replies
7
Views
698
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 22 ·
Replies
22
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 60 ·
3
Replies
60
Views
7K