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Homework Help: Incline Problem

  1. Jan 12, 2014 #1
    1. The problem statement, all variables and given/known data

    A dog pulls the rope of a 50 kg sled up a hill with an incline of 20° above the horizontal. The rope is directed 30° from the slope and the dog exerts a force of 200N on the rope. The force of friction is 50 N. What is the sled's acceleration?

    2.The attempt at a solution

    Fnet = ma

    (Fapp) - (Ffriction) - (Fgx) = (50)(a)

    (200N cos30) - (50N) - (50 kg * 9.81 m/s/s * sin20) = (50) (a)

    a = -0.89 m/s/s.

    Therefore, the sled is going down hill?!
  2. jcsd
  3. Jan 12, 2014 #2
    I did the problem and got the same results, I cannot help.

    You should change your dog :), or maybe we are doing some mistakes, who knows.
  4. Jan 12, 2014 #3
    The pooch is too weak. It makes sense too, though, he has to pull a 50kg sled with only an initial 200N of horsepower to work with.
  5. Jan 12, 2014 #4
    Even without the 30º the dog cannot pull the sled, maybe the teacher shows this to explain why you need a bunch of dogs pulling the sled :) .
  6. Jan 12, 2014 #5
    Thanks guys. I guess i did it correctly.
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