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Homework Help: What mechanical paramater has a unit corresponding to expression

  1. Nov 16, 2009 #1
    1. The problem statement, all variables and given/known data
    What mechanical parameter has a unit corresponding to expression N2 sec3/kgm ?

    2. Relevant equations
    a.impulse b.time c.velocity d.energy e.force

    3. The attempt at a solution
    i need your help. please take a look this.
    thanks in advance.
  2. jcsd
  3. Nov 16, 2009 #2
    do you know what a newton is in SI units?
  4. Nov 16, 2009 #3
  5. Nov 16, 2009 #4
    no, a newton is the unit of force but a newton can be broken down into simpler units of measure. this is the equivalency:

    [tex][N]=[\frac{Kgm}{s^2}][/tex] -(these are the units for F=ma)

    This should make sense to you, F=ma. "m" is measured in Kg, "a" is measured in m/s^2. when you multiply the two you get a unit of Newton
  6. Nov 16, 2009 #5
    thanks for your response. but then the answer of question is Force ? right.
  7. Nov 16, 2009 #6
    no, plug the SI expression for a Newton into the original expression, what units are left?
  8. Nov 16, 2009 #7
    impulse ?
  9. Nov 16, 2009 #8
    you got it! ^^
  10. Nov 16, 2009 #9
    ah thanks! :) you are helpful. i did it by thinking. at last i did a physics test my own (of course with your help)
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