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Homework Help: Dynamics wagon problem

  1. Nov 3, 2014 #1
    • Member warned about not including efforts
    1. The problem statement, all variables and given/known data
    A child is pulling a wagon of mass 7.38 kg up a hill inclined at an angle of 14.3° to the horizontal. The child applies a force parallel to the hill. The acceleration of the wagon is 6.45 cm/s2 up the hill. Friction is negligible. Determine the magnitude of (a) the force applied by the child, and (b) the normal force on the wagon.

    2. Relevant equations

    3. The attempt at a solution
    Last edited: Nov 3, 2014
  2. jcsd
  3. Nov 3, 2014 #2


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    Homework Helper

    You might need some directional components for this one. Try drawing a diagram.
  4. Nov 3, 2014 #3


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    Gold Member

    We need to have an FBD for the wagon.
  5. Nov 3, 2014 #4
    Is there any other way this problem can be solved?
  6. Nov 3, 2014 #5


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    Oh, I suppose you could just guess.
  7. Nov 3, 2014 #6
    Last edited: Nov 3, 2014
  8. Nov 3, 2014 #7


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    a) F = ma, what's F in this case?
    b) N = mgcosθ
  9. Nov 3, 2014 #8
    thank you for your help td21 :)
  10. Nov 3, 2014 #9
    I understand b) now thanks :D but a) I am still having trouble understand how it is solved
  11. Nov 3, 2014 #10


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    1. List all the forces acting on the wagon.
    2. For each force, determine the component of it parallel to the slope.
    3. Write an equation corresponding to ##\Sigma F = ma## for the forces and acceleration parallel to the slope.
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