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Why is work equal to F x S ?

  1. Feb 15, 2012 #1
    Its known that Work=Force X Displacement or F x S.
    But why?
    Why is only F x S equal to work?
    Why not something else like Work=blah X blah could be true?
  2. jcsd
  3. Feb 15, 2012 #2
    As far as I understand it, its a fundamental definition so its not derived, its a definition. The force exerted on a physical system and the distance in the force direction are both proportional to the potential that physical system gains for exerting a force through some distance, i.e. potential for work, aka "energy". So this quantitative definition of work results in transfer of energy, our qualitative definition of work.

    If my understanding is wrong, someone please do give me some constructive criticism.
  4. Feb 15, 2012 #3


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    Work / energy can take many forms, in fact.
    It can be:
    Pressure times volume change.
    Torque times angle
    Charge times Potential difference

    You could say it's a definition but it's more than that. It's not just arbitrary because you can transfer work, defined one way, into work, defined another way and then into Heat (internal energy).

    It's a quantity that Science has found useful to deal in.
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