1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Equilibrium of Particles

  1. Feb 6, 2015 #1
    1. The problem statement, all variables and given/known data
    Here is the problem that I am stuck on in my mechanics class.

    2. Relevant equations

    3. The attempt at a solution
    See the attached picture of my work
    I'm so stuck. I don't know what to do from here.
  2. jcsd
  3. Feb 6, 2015 #2


    User Avatar
    Homework Helper

    Why do you think the change in length of spring AB is 3 meters?

    Just a tip, there's no reason to find the angles spring AB makes; you only care about the sine or cosine of the angles which corresponds to ratios of the sides of the triangle. Finding (and rounding) the angle, like you did, may lead to less accuracy in the final answer.
  4. Feb 6, 2015 #3


    User Avatar
    Homework Helper

    Now, about your main problem:

    What can you say about the ratio between "Facx" and "Facy"?
  5. Feb 6, 2015 #4


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Because the unstretched length has been taken as 2m instead of 3m.
  6. Feb 7, 2015 #5
    tan(45)=FACy/FACx or, they're directly proportional bc tan(45) = 1
    FACy = FACx
    What do I do with this?
  7. Feb 7, 2015 #6


    User Avatar
    Homework Helper

    You calculated FACx so now you know FACy. You also calculated FABy. So what is the weight of block D?

    But actually you calculated incorrectly, you'll need to recalculate (but I think you had the right idea). The problem says the unstretched length is 3 meters, not 2 meters.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Equilibrium Particles Date
Simple Harmonic Motion and equilibrium of springs Jun 9, 2017
Particle equilibrium Sep 30, 2016
Problem Check: Equilibrium of Particles Feb 11, 2015
Equilibrium of a Particle Feb 6, 2015
Equilibrium of a Particle Nov 19, 2014