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Homework Help: Work on an Incline

  1. Mar 29, 2004 #1
    Test tomorrow an im sure somthing like this will be on it. What is needed to find out the work done upon a 50.0-kg cylinder that is being pushed up a 3-m high, 6-m long (hypotonuse) ramp?
  2. jcsd
  3. Mar 29, 2004 #2
    The mass of whatever's being pushed, the coefficient of friction between whatever's being pushed and the ramp, and any two of the following: the length of the ramp, the height of the ramp, the hypotenuse of the ramp, the angle of elevation of the ramp.

  4. Mar 29, 2004 #3
    Mind checkin this?

    Is this correct? :

    Sin^-1(3/6) = 30°

    50.0 x 9.8 = 490-N

    Sin30(490) = 245-N

    W= 245 x 6 = 1476-J

    Oh and theres no friction needed.
    Last edited: Mar 29, 2004
  5. Mar 29, 2004 #4
    Ah... Looks right to me.

  6. Mar 30, 2004 #5
    If there is no friction, you can just use the potential energy of the object. You know that at the bottom of the ramp, its potential energy is zero. You also know that at the top of hte ramp, its potential energy is [itex]mgh[/itex]. You also know that the work done by non-conservative forces is equal to the change in mechanical energy of the object. Therefore:
    [tex]W = \Delta E_M = \Delta E_p = mgh = 50kg * 9.8\frac{m}{s^2} * 3m = 1470J[/tex]
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