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Homework Help: Find acceleration only given distance of slop and angle of elevation.

  1. Jul 14, 2007 #1
    1. The problem statement, all variables and given/known data

    A puck is let go on the top of a frictionless slope. The slope is length .74 m and 3.5 degrees above the horizontal. What is the acceleration and how long does it take the puck to go down the slope?


    2. Relevant equations

    Fnet=ma
    Fg=mg?


    3. The attempt at a solution

    If I was given m, I could just draw a free body diagram and find Fnet down the slope and then use m to find acceleration using Fnet=ma

    Without mass, I am quite lost? Can it be done?
     
  2. jcsd
  3. Jul 14, 2007 #2

    Doc Al

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    Staff: Mentor

    You don't need a specific value for mass to draw a free body diagram--just call it "m". Hint: Perhaps the answer doesn't depend on m. :wink:
     
  4. Jul 14, 2007 #3

    robphy

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    Science Advisor
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    Gold Member

    Although you're not given an explicit value for m,
    can you attempt to solve the problem assuming a nonzero value for m?
    If you can, you might see why an explicit value wasn't given.

    [ doh.... i hesistated too long [by rereading my post] o:)]
     
  5. Jul 14, 2007 #4
    Thanks Doc Al :D
     
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