I bought this truck crane for my dad. I want to calculate the mechanical advantage of it. http://www.harborfreight.com/1-2-half-ton-capacity-pickup-truck-crane-1647.html [Broken] I know how to calculate the mechanical advantage of a hydraulic jack and of a lever but im not sure about where they connect to each other. When the jack lengthens it rotates back so the different angles change. How do i calculate that? Where do i start. Does it involve the law of cosines and calculus or something simpler?