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Power, Work and Force

  1. Feb 20, 2016 #1
    1. The problem statement, all variables and given/known data
    An elevator cab has a mass of 4600 kg and can carry a maximum load of 1800 kg. If the cab is moving upward at full load at 4.50 m/s, what power is required of the force moving the cab to maintain that speed?

    2. Relevant equations
    P = W/T
    W = F*D
    F = M*A
    3. The attempt at a solution
    P = W/T
    P = (F*D)/T
    P = ((M*A)*D)/T
    P = ((6400*9.8)*D)/T
    I don't know what I should enter for D and T
    Help, please?
     
  2. jcsd
  3. Feb 20, 2016 #2

    PhanthomJay

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    D/T is equal to what ? (using kinematic equations ).
     
  4. Feb 20, 2016 #3
    Distance and Time
     
  5. Feb 20, 2016 #4

    PhanthomJay

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    Distance divided by time equals _____? (Fill in the blank)
     
  6. Feb 20, 2016 #5
    oh velocity
     
  7. Feb 20, 2016 #6
    so the answer would be 6400*9.8*4.5 = 282240 Watts?
     
  8. Feb 20, 2016 #7

    PhanthomJay

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    Well, D/T is average or constant speed , which is given.
     
  9. Feb 20, 2016 #8
  10. Feb 20, 2016 #9

    PhanthomJay

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    Yes. You should round it off to say 280 kW.
     
  11. Feb 20, 2016 #10
    But 282.240 kW is the non rounded answer?
     
  12. Feb 20, 2016 #11

    PhanthomJay

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    Yes.
     
  13. Feb 20, 2016 #12
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