[BASIC] Interpretation of multiplication

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Discussion Overview

The discussion revolves around the interpretation of multiplication in the context of physics, particularly focusing on how different units interact when multiplied. Participants explore the implications of formulas related to momentum and energy, seeking a deeper understanding beyond their definitions.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant expresses confusion about the meaning of multiplying variables with different units, specifically in relation to physical formulas like momentum and energy.
  • Another participant clarifies that momentum is defined as mass multiplied by velocity, noting the scalar nature of mass and the vector nature of velocity, which has units of distance per time.
  • A participant questions the rationale behind the formulas for momentum (p=mv) and energy (W=fd), seeking an intuitive understanding of why momentum is represented as the product of mass and velocity.
  • One response reinforces the intuitive notion that greater momentum implies greater resistance to changes in motion, linking this idea to the conditions under which momentum can be zero.
  • Another participant states that the formulas for energy and momentum are structured to ensure conservation of these quantities under specific circumstances, indicating that this structure was derived from empirical observations.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the formulas for momentum and energy, with some seeking clarification while others provide insights. No consensus is reached on the intuitive reasoning behind these formulas.

Contextual Notes

Participants have not fully resolved the underlying assumptions about the nature of multiplication in physics or the specific conditions under which the conservation of momentum and energy applies.

Atran
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Hello, I know this question may be absurd or very basic, but I need to know what it means when two variables with different units are being multiplied.

I need to know what multiplication is in physics, in order to make sense of formulas (such as momentum, force, energy formulas) without only depending on their written definitions.

Thanks for help.
 
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You need to clarify what is troubling you. For example momentum = mass x velocity, where mass is scalar in units such as grams, while velocity is a vector where the components are in units of distance divided by time, such as meters per sec.
 
I don't understand why momentum (p=mv) and energy (W=fd) formulas are the way they are.

I've got an intuitive feeling of momentum: the greater momentum an object has, the more resistance it has for change in motion.

I don't really understand why momentum is equal to (mv). In other words, why (mv)?
 
the greater momentum an object has, the more resistance it has for change in motion.

You've essentially captured it in that statement.

Think about what happens if EITHER of those quantities is 0. A massless object has no resistance to change, and a motionless object has no motion. Both or either one imply 0 momentum.
 
The formulas for energy and momentum are chosen such that those quantities are conserved under certain circumstences. That is the whole point of these two concepts. The conservation of these qunatities was deduced empirically.
 

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