Why only two kinds of vector products defined?

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Discussion Overview

The discussion revolves around the question of why only the dot product and cross product are commonly defined for vector multiplication in physics, while other potential vector products, such as the proposed A#B, are not utilized or required in physical applications. The scope includes theoretical considerations and practical applications in physics and engineering.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant proposes a new vector product, A#B, defined as ABcos@i, questioning its absence in physics and the sufficiency of the dot and cross products.
  • Another participant suggests that the initial question becomes obsolete upon defining a new vector product.
  • A later reply emphasizes that the dot and cross products are the most useful for solving problems in physics and engineering, particularly in contexts like work done and torque.
  • Some participants note that there are indeed other vector products defined, referencing external sources, but imply that these are not commonly encountered in typical physics problems.
  • It is mentioned that the dot and cross products are taught first due to their widespread applicability in foundational physics and engineering.

Areas of Agreement / Disagreement

Participants express differing views on the necessity and utility of other vector products beyond the dot and cross products. While some acknowledge the existence of other products, there is no consensus on their relevance or application in standard physical scenarios.

Contextual Notes

Limitations include the potential for other vector products to be useful in specific contexts that are not commonly studied, as well as the dependence on the definitions and applications of vector multiplication in various fields.

Sunny Singh
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Why only the dot and cross product for vector multiplication is defined and not another kind of vector product like one in which the magnitude is that of the dot product and direction is of the cross product. I mean if A and B be two vectors then let there be a vector product such that A#B=ABcos@i where @ is the angle between A and B and i is the direction perpendicular to both of them described by right hand screw rule. Why don't we encounter any situation in Physics where such a vector product is required?? Why is the dot and cross product sufficient?
 
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Sunny Singh said:
Why only the dot and cross product for vector multiplication is defined and not another kind of vector product...
You have just defined another kind of vector product. So your question is now obsolete.
 
A.T. said:
You have just defined another kind of vector product. So your question is now obsolete.
sorry my question was incomplete at that time. i want to ask why only dot and cross product is required in physics like when calculating work done and Torque? why any other type of vector product is not required for any physical situation and hence not defined?
 
Sunny Singh said:
sorry my question was incomplete at that time. i want to ask why only dot and cross product is required in physics like when calculating work done and Torque? why any other type of vector product is not required for any physical situation and hence not defined?

Those two are the ones that have been found to be most useful (in the sense of being good tools for solving problems) in all the physics that you'll be studying before you to get to quantum mechanics. They're also needed for much of engineering and mechanical design. Thus, they're the ones that get taught first and most widely.

As other posters in this thread have pointed out, there are other possible vector products as well - most people just never never encounter them because they never study the sorts of problems in which they would be useful.
 

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