What does the hauling part move through in a block and tackle system?

In a block and tackle system, the hauling part, which is the rope or line used to lift or pull a load, moves through the movable part of the system. The movable part is typically a block that has one or more sheaves (pulleys) that allow the line to pass through while reducing the effort needed to lift a heavy load.

By utilizing the mechanical advantage provided by the arrangement of the pulleys, the hauling part effectively redistributes the load and provides greater lifting power with less force applied. This design is essential for applications where heavy lifting is required, as it maximizes efficiency and safety.

The other choices—fixated points, static lines, and support beams—do not accurately describe where the hauling part of the system interacts or operates. Fixed points are stationary anchors; static lines do not allow movement; and support beams are structural elements that provide stability. Hence, the correct characterization of the hauling part's function is that it moves through the movable part, which facilitates the operation of the block and tackle system.