1. The problem statement, all variables and given/known data A collar with a pulley slides on a frictionless vertical bar GH. A string A B C D is wrapped around, where portion AB of the string is horizontal. A spring with 2.5 lb/in. stiffness is placed between the collar and point H. The spring has 7 in. unstreched length and 5 in. final length. The collar and pulley have a combined weight of 3.1 lb, and the weights of all other components are negligible. Determine the value of P required for equilibrium, and the magnitude of the reaction between the collar bar GH. Picture: http://imgur.com/nHj2rrB Hint given: Before taking any other action, draw a FBD of the collar/pulley. This requires a closed external surface passing though the string at two locations as well as between the contact point between the spring and collar/pulley, and internal surface passing through the interface with the smooth bar. Pay close attention to the direction of the force exerted on the collar/pulley by the spring given the information in the problem statement. 2. Relevant equations ΣF=0 ΣFxi+ΣFyj=0, ΣFx=0, and ΣFy=0. Spring Law: Fs=kδ=k(L-L0) 3. The attempt at a solution Here's my (attempted) FBD: http://imgur.com/YdaoEEW I know it's probably incorrect, we never really did an example in class that involved springs. Also I wasn't sure what should have been in the middle B or C? B and C? Only B? Only C? Two body diagrams? I know I need to add up all the x and y components then for P figure out the force it takes to make the x components equal 0. Then from there finding the magnitude of HG is just a matter of adding together their components and taking the magnitude. I seem to have a really hard time figuring out the components, but when I find them I can pretty easily finish the problem. Thank you so much for any help!