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 force equilibrium problem involving simply pully syst

  1. Jul 3, 2015 #1
    1. The problem statement, all variables and given/known data
    A former student of mechanics wishes to weigh himself but has access only to a scale A with capacity limited to 120 lbs and a small 20-lb spring dynamometer B. With the rig shown he discovers that when he exerts a pull on the rope so that B registers 19 lb, the scale A reads 96 lb. What is his correct weight?


    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jul 3, 2015 #2
    Take more care to only add all the forces acting on an object. If a weight is only acting through a tension, then you add only the tension not the weight too.
  4. Jul 3, 2015 #3
    yes of course. ΣFy= -19-96+4TB-TA=0 thanks Dr
  5. Jul 3, 2015 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Unfortunately, we can't open that link from Wiley without a username/password.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted