Why we don’t put a minus sign in Coulomb's law

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Discussion Overview

The discussion revolves around the question of why a minus sign is not included when calculating the force between two charges in Coulomb's law. Participants explore the implications of charge signs and their relationship to force direction and acceleration, focusing on conceptual understanding rather than mathematical derivation.

Discussion Character

  • Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants suggest that like charges repel, leading to a positive acceleration and thus a positive force according to conventional definitions.
  • Others argue that if distances from the origin are considered positive, the resulting force from like charges should also be positive, aligning with the established conventions.
  • A participant notes that including a minus sign with each charge would result in two minus signs, which would mathematically yield a positive result, questioning the necessity of the minus sign.
  • Another viewpoint compares the treatment of charge signs to the use of variables in algebra, suggesting that the framework of arithmetic does not change based on the positivity or negativity of the variables involved.

Areas of Agreement / Disagreement

Participants express differing views on the necessity and implications of including a minus sign in calculations involving Coulomb's law, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Limitations include the lack of a detailed mathematical framework to support the claims made and the dependence on conventional definitions of force and charge signs.

Zain580
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While calculating the force between two charges , why we don't put minus sign with charge.
 
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Zain580 said:
While calculating the force between two charges , why we don't put minus sign with charge.

Because like charges repel: that is, the force between them makes them accelerate away from each other, which is a positive acceleration (positive sign of force) according to the usual convention.
 
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If you start with distances from origin as positive and the sign of a Force corresponding to the same direction (which makes sense) then like charges will produce a positive force etc..
 
Zain580 said:
why we don't put minus sign with charge.

This is a slightly different question than the title. If you put it with each charge, you will have two minus signs which will result in a plus.
 
Zain580 said:
why we don't put minus sign with charge.
For the same reason that we use x on a graph when the value of x can be positive or negative. That's a general thing with Algebra. If it didn't work that way, we' have to have different arithmetic depending on whether the variables we used were positive or negative.
 

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