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Homework Help: Work and refrigerator energy

  1. Feb 23, 2008 #1
    1. The problem statement, all variables and given/known data

    A mover's dolly is used to deliver a refrigerator up a ramp into a house. The refrigerator has a mass of 110 kg. The ramp is 2.1 m long and rises 0.42 m. THe mover pulls the dolly with constant velocity and with a steady force of 445 N up the ramp. The dolly and ramp constitute a machine. g=9.81/s^2

    What work does the mover do?

    The attempt at a solution

    well i thought that this was a simple question. I used W=F*x using 445 N as F and 2.14 M as x which i got from using the pythagorean theorem. My final answer was 953.007 J but it was incorrect. Can someone help me understand what I'm doing wrong?
  2. jcsd
  3. Feb 23, 2008 #2


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    Science Advisor

    You are told that the ramp is 2.1 m long. The ramp is not lying on the ground! The ramp is the hypotenuse of the right triangle. Looks to me like you should just have 445*2.1!
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