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!

Static equilibrium; pulley and inclined plane problem.

  1. Jul 3, 2015 #1
    1. The problem statement, all variables and given/known data
    What weight WB will cause the system to be in equilibrium? Neglect all friction, and state any other assumptions.
    20150703_125114_zpskvhgwrb0.jpg
    2. Relevant equations
    ΣF=0

    3. The attempt at a solution
    I cant figure out what im doing wrong with these pully problems, I tried putting in resultant forces at pully A, but that just added another variable.

    20150703_124617_zpsxzgyk5c7.jpg
     
  2. jcsd
  3. Jul 3, 2015 #2
    You should check the Wb is Tb or ___ ?
     
  4. Jul 3, 2015 #3
    I did a redo of the tensions this time starting from A going to B, im still missing something though. solving for weight at B i got 8.72lb (on the right side of my paper)
    20150703_131312_zps5z8gcb8z.jpg
     
  5. Jul 3, 2015 #4
    It seems correct to me.
     
  6. Jul 3, 2015 #5
    Yea, but im still missing something, its not the correct answer.
     
  7. Jul 3, 2015 #6
    Oh, find the F again you will see the wrong :) 79,5 N or kg ?
     
  8. Jul 3, 2015 #7
    If the weight of block A is 175 lb that is equal to 79.5N
     
  9. Jul 3, 2015 #8
    ok i got, my mistake was trying to convert from english to standard, i should of just left it in english. thanks thypon.
     
  10. Jul 3, 2015 #9
    No, 1lb is equal to 0,453 kg, so 175lb =79,27 kg
    N means kg*m/(s^2)
     
  11. Jul 3, 2015 #10
    i got confused because 175 lb of weight = 175 lb mass.
     
  12. Jul 3, 2015 #11
    Is it okay now ?
     
  13. Jul 3, 2015 #12
    yea its correct now. thanks
     
  14. Jan 25, 2017 #13
    Why is the tension T/2?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Static equilibrium; pulley and inclined plane problem.
Loading...