What is a lever arm?

A lever arm is defined as the distance from the fulcrum to the point where the input force is applied. This concept is crucial in understanding how levers operate, as the lever arm influences the mechanical advantage that a lever can provide. The longer the lever arm, the less input force is needed to lift a heavier load, making it easier to perform work.

In practical applications, the effective length of the lever arm can determine how much force is exerted at the load end. Thus, by manipulating the position of the input force along the lever arm, one can significantly impact the system's efficiency and force requirements. This relationship underscores the importance of the lever arm in leveraging forces for lifting or moving objects.