let f be the cable tension and vb be the velocity of collar b when it strikes the support. consider the collar b. its movement is horizontal so only horizontal forces acting on b do work. let d be the distance through which the 30 lb applied force moves. 1 12 2 2 () ( ) () 1 18 0 30 (2 )(2) 2 32.2 b bb b tu t df v      2 30 4 0.27950 b df v   (1) now consider the weight a. when the collar moves 2 ft to the left, the weight mo