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Homework Help: Box Sliding Up a Ramp

  1. Feb 7, 2007 #1
    1. The problem statement, all variables and given/known data
    You are working for a shipping company. Your job is to stand at the bottom of a 8.0-m-long ramp that is inclined at 37 degrees above the horizontal. You grab packages off a conveyor belt and propel them up the ramp. The coefficient of kinetic friction between the packages and the ramp is .30 What speed do you need to give a package at the bottom of the ramp so that it has zero speed at the top of the ramp?


    2. Relevant equations
    [tex]x = x_0 + v_0 t + (1/2) a t^2[/tex]

    [tex]v = v_0 + a t[/tex]

    [tex]v^2 = v_0^2 + 2 a \Delta x[/tex]

    [tex]\vec{F}_{net} = \Sigma \vec{F} = m \vec{a}[/tex]


    3. The attempt at a solution

    Well first I drew a digram which gave me a component of [tex]nsin37[/tex] as the force acting down the ramp and then of course the nu force of friction. SO, then I wrote out that

    as

    [tex]\vec{F}_{net} = \Sigma \vec{F} = m \vec{a} = -mgsin37 - .30mg + F_t[/tex]

    With [tex] F_t [/tex] being the force of the throw

    Then I know that since I'm solving for the initial velocity that should be related to the acceleration and the force through

    [tex]v = v_0 + a t[/tex]

    but I'm not sure how. I haven't been given the value for the mass, so I'm not sure if I can even solve this problem only using the given variables.
     
    Last edited: Feb 7, 2007
  2. jcsd
  3. Feb 7, 2007 #2

    radou

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    Homework Helper

    Ok, and where's the problem in the text? :wink:
     
  4. Feb 7, 2007 #3
    oops... fixed it.
     
  5. Feb 7, 2007 #4
    Am I missing something, just below where it is lopped off in the quote. was there an edit?

    Rob, anyway its a bit like the last one, the masses all divide out.
     
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