452. You are using tackle number 7 in illustration D029DG below to lift a weight of 100 lbs. If you include 10 percent of the weight for each sheave for friction, what is the pull on the hauling part required to lift the weight?

The pull on the hauling part is calculated by first determining the mechanical advantage (2:1 for a single movable sheave), then accounting for friction (10% of the 100 lb load, or 10 lbs), resulting in an effective load of 110 lbs. Dividing the effective load by the mechanical advantage yields a required pull of 55 lbs.