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Homework Help: Pascals Principle & Efficiecy related problem

  1. Oct 11, 2012 #1
    1. The problem statement, all variables and given/known data
    The input and output pistons of a hydraulic jack are respectively 1 cm and 4 cm in diameter. A lever with a mechanical advantage of 6 is used to apply force to the input piston. How much mass can the jack lift if a force of 180 N is applied to the lever and efficiency is 80%?

    2. Relevant equations

    3. The attempt at a solution
    1410.6 kg
    The above question is from a NASA webpage and the answer they provided is 1410.6 kg

    Can any one please tell me how do solve it ?
  2. jcsd
  3. Oct 11, 2012 #2
    Do it in steps.

    1. Compute the force applied to the input cylinder by the lever.

    2. Compute the force produced by the output cylinder.

    3. Take efficiency into account.
  4. Oct 13, 2012 #3
    I really don't understand the lever involving part and how to compute the input force,
    isnt it 180 newton as given above? please help me through this problem
  5. Oct 13, 2012 #4
    180 N is the force applied to the lever. The lever has a certain mechanical advantage, so it transforms this force into another force, which is then applied to the cylinder. What is this latter force?
  6. Oct 14, 2012 #5
    Hmm, How do I calculate the input force by lever :

    Please can you do the solution for me once.
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