What is the formula to find the ideal mechanical advantage of a lever?

The formula to find the ideal mechanical advantage (IMA) of a lever is based on the lengths of the lever arms. Specifically, IMA is calculated by dividing the length of the load arm by the length of the effort arm. The load arm is the distance from the fulcrum to the load, while the effort arm is the distance from the fulcrum to where the effort is applied.

This relationship illustrates that as the load arm increases relative to the effort arm, the mechanical advantage increases, allowing a smaller effort to lift a heavier load. This principle is fundamental in understanding how levers work, emphasizing that the configuration of the lever can significantly impact its efficiency in moving loads.

The other options don't accurately represent the relationship of the lever arms or confuse the terms regarding the forces and distances involved. Hence, the choice that states the IMA is calculated as the load arm divided by the effort arm is the correct formulation for determining the ideal mechanical advantage in a lever system.