What is the relationship between force and distance in an inverse square law?

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Discussion Overview

The discussion revolves around the relationship between force and distance in the context of inverse square laws, specifically examining the properties and implications of such laws in physics. Participants explore various statements related to gravitational and electrostatic forces, debating their correctness and general applicability.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant suggests that the gravitational force equation indicates that the force decreases with distance, supporting option (b).
  • Another participant agrees that (b) is correct but argues that options (a), (c), (d), and (e) can be ruled out based on specific laws, such as Coulomb's law and Newton's law.
  • A participant cites Newton's law of gravitation to argue that options (b), (c), and (e) are correct, emphasizing the role of mass and the universal constant.
  • There is a contention regarding the generality of options (c) and (e), with some participants asserting that these do not apply universally to all inverse square laws.
  • One participant expresses concern about the wording of the question, suggesting it is poorly constructed.

Areas of Agreement / Disagreement

Participants generally agree on the correctness of option (b) regarding the decrease of force with distance, but there is disagreement on the applicability of options (c), (d), and (e) to the general case of inverse square laws. The discussion remains unresolved regarding the interpretation of these options.

Contextual Notes

Some participants highlight that the question may not clearly differentiate between specific cases (like gravitational and electrostatic forces) and the general concept of inverse square laws, leading to confusion about the applicability of certain statements.

berge616
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I am confused regarding the following question. My guess is that b is correct, because the gravitational force equation has r^2. However beyond that I am not sure if any other options are correct. Please help


What do you know about a force that follows the inverse square law.
(a) The force is strong.
(b) The force decreases with distance.
(c) The force depends on the magnitude of the masses involved.
(d) The force depends on the magnitude of the charges involved.
(e) The force depends on a universal constant.
 
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You are correct in saying it is (b). (a) does not say anything in general about the law, (c) and (d) can be ruled out by giving coulomb's law and Newton's law respectively and (e) can be ruled out by using as an example the inverse square law that determines the intensity of radiation, emitted at a point source and distributed spherically, at a distance r from the source which does not include any universal constant. (b) is part of the definition of an inverse square law.
 
Newton's law: F=Gm1m2/r2, where the m's are the masses involved, r is the separation, and G is a universal constant. Therefore b, c, and e are all correct.
 
mathman said:
Newton's law: F=Gm1m2/r2, where the m's are the masses involved, r is the separation, and G is a universal constant. Therefore b, c, and e are all correct.

The question is asking about inverse square laws in general though. (c) and (e) are not general cases.
 
Last edited:
WannabeNewton said:
The question is asking about inverse square laws in general though. (c) and (e) are not general cases.
The question is very badly worded.
 

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