1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Static equilibrium ship problem

  1. Nov 9, 2009 #1
    1. The problem statement, all variables and given/known data

    You are on a pirate ship and being forced to walk the plank. You are standing at the point marked C. The plank is nailed onto the deck at point A, and rests on the support 0.75 meters away from A. The center of mass of the uniform plank is located at point B. Your mass is 67 kg and the mass of the plank is 45 kg.

    see link for a picture of the the above problem

    2. Relevant equations

    3. The attempt at a solution

    I figured that the force of the nails F_n has to equal the force of the weight of the man plus the weight of the board and the sum of the forces must equal zero but ended up with the wrong solution

    Attached Files:

  2. jcsd
  3. Nov 11, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    What's the question?
    When summing vertical forces, you must also include the force from the support located 0.75 m from A. You'll need to sum moments about a convenient point to satisfy sum of moments = 0, for the equilbrium condition.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook