What is the mechanical advantage of a lever?

The mechanical advantage of a lever is defined as the ratio of the load force (the weight being lifted or the resistance) to the effort force (the force applied to lift the load). This ratio determines how much the lever amplifies the input force. A higher mechanical advantage means that less effort is required to lift a heavier load, illustrating the effectiveness of the lever in reducing the force needed to do work. In practical terms, if the mechanical advantage is greater than one, it indicates that the lever is allowing you to lift a heavier load than the force you are applying, demonstrating one of the key benefits of using simple machines like levers.

In contrast, the other choices do not accurately represent the concept of mechanical advantage. The difference or sum of load and effort forces do not convey how effectively a lever amplifies force, and net force does not specifically measure the relationship between load and effort in the context of mechanical advantage.