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Homework Help: Energy elevator problem

  1. Dec 4, 2008 #1
    1. The problem statement, all variables and given/known data

    A 1200kg elevator driven by an electric motor can safely carry a maximum load of 800kg. What is the power provided by the motor when the elevator ascends with a full load at a speed of 2.3 m/s

    2. Relevant equations

    P=F*v

    3. The attempt at a solution

    So I use directly P=F*v=(melevator+mpeople)*g*v

    However I got the wrong answer. Does it involve any other formula here ?
     
  2. jcsd
  3. Dec 4, 2008 #2

    alphysicist

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    Homework Helper

    Re: Energy

    Hi nns91,


    What answer did you get?
     
  4. Dec 4, 2008 #3
    Re: Energy

    Dont you calculate the weight acting downwards so

    w=mg

    where the mass is 1200+800=2000kg

    multiplied by g = 9.81ms^-2

    so f downwards or the weight = 19620

    then put it in

    p=fv

    so p= 19620 x 2.3

    p= 45126 w


    thats how i would do it dunno if im right =]
     
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