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Homework Help: Simplifying SI units

  1. Jan 20, 2016 #1
    1. The problem statement, all variables and given/known data
    What physical quantity does ##\mathrm{J\cdot N\cdot W^{-1}\cdot kg^{-1}}## denote?

    2. Relevant equations
    You can simplify using mechanics equations or ones from electrodynamics. Be creative, I guess.

    3. The attempt at a solution
    ##\mathrm{J\cdot N\cdot W^{-1}\cdot kg^{-1}}## simplifies to ##\mathrm{s\cdot N\cdot kg^{-1}}##. I don't know how to continue from this point.

    Thanks in advance!
  2. jcsd
  3. Jan 20, 2016 #2


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    Staff: Mentor

    Expand the Newton. Think f = ma.
  4. Jan 20, 2016 #3


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    Gold Member

    Do you know the definition of N?
  5. Jan 20, 2016 #4


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    Science Advisor
    Homework Helper

    ##N## is unit of force, how can you further write it in terms of fundamental units?
  6. Jan 20, 2016 #5
    Velocity it is. Thanks for the help everyone! I was never taught what the exact definition of the newton was.
  7. Jan 20, 2016 #6


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    Science Advisor
    Homework Helper

    Just rewriting units in terms of others does not really require you to know its definition. Just use any formula you know in which force is involved, like work being equal to force times distance (for constant force).
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