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An incline problem

  1. Feb 27, 2007 #1
    1. The problem statement, all variables and given/known data
    a toy cart of mass 5kg is projected up a ramp incined at 30 degree to the horizontal, with an initial velocity of 6m/s. if the frictional force opposing its motion is 4N, find the distance it travels before stopping, and its increase in gravitational potential energy at that point.

    2. Relevant equations
    v2^2 = v1^2 + 2ad

    3. The attempt at a solution
    so using vector, mgsin30 - 2 = ma
    24.5 = 5a

    sub into
    v2^2 = v1^2 + 2ad
    and i got 36/1.8 = 20 = d but it is very different from answer of the book
    please help me to solve it
  2. jcsd
  3. Feb 27, 2007 #2


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    Homework Helper

    Why do you have that as 2? It says the force of friction is 4 N. By the way, if the cart is being pushed up the ramp, the frictional force and the gravitational force act in the same direction. So how does that change things? Did you draw a free body diagram?
  4. Feb 27, 2007 #3

    Doc Al

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    Staff: Mentor

    You'll need to redo this calculation. Your initial equation is not quite right. What forces act on the cart? (Include both gravity and friction.) In which direction do those forces act? What's the net force acting on the cart?
  5. Feb 27, 2007 #4
    oh thank you, now i get this question..what a silly mistake i made..
  6. Mar 23, 2007 #5
    omg. it's the same problem that I am working on right now.

    but i need to solve it using the concept of conservation of energy. anyone knows how?
  7. Mar 23, 2007 #6


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    Homework Helper

    What have you tried? Show some of your work.
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