Pulley If there are "p" of these parts of the rope supporting the load "W," then a force balance on the moving block shows that the tension in each of the parts of the rope must be "W/p." This means the input force on the rope is "T"="W/p." Thus, the block and tackle reduces the input force by the factor "p." The simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless, and that there is no energy loss due to friction. It is also assumed that the lines do not stretch. In equilibrium, the
Miztec (schooner barge) the State of Michigan after they were seized in a 1992 Michigan Department of Natural Resources and Environment (DNRE) raid on the Great Lakes Shipwreck Museum. The State allows the museum to hold a triple sheave block and hook and a double sheave block and hook from the "Miztec" as a loan. Her wreck is now protected by the Whitefish Point Underwater Preserve as part of an underwater museum. The 194 foot wooden "Miztec" was built as a 3-masted schooner in 1890 in Marine City, Michigan. She was enrolled at Port Huron, Michigan on 8 April 1890. On 3 May