Summary

In this particular application, we see:

a. The force necessary to lift the weight is equal to half the weight. Therefore the mechanical advantage is 2.

b. By applying a downward force, we were able to lift a weight upward. Therefore the pulley changes the direction of the force necessary to lift the weight. (If we had not used the pulley, we’d have needed to use an upward force to lift the weight).

c. To lift the weight by one foot we have to pull the rope down by two foot.