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What formula is used to calculate mechanical advantage in a system?

  1. Radius of axle × radius of drum

  2. Radius of drum / radius of axle

  3. Radius of axle / radius of drum

  4. Diameter of axle / diameter of drum

The correct answer is: Radius of axle / radius of drum

The formula used to calculate mechanical advantage in a system involving pulleys or wheels is based on the relationship between the radius of the drum and the radius of the axle. The correct formula is the radius of the drum divided by the radius of the axle. This relationship allows one to determine how much easier a task can be performed using a mechanical system. Specifically, if the radius of the drum is larger than that of the axle, the mechanical advantage increases, allowing a smaller force to move a larger load. The principle is grounded in the concept of leverage, where larger radii provide a greater leverage effect, reducing the effort needed to perform work. While options involving the multiplication of the radii or using diameters might suggest a relationship, they do not accurately represent the calculation of mechanical advantage in this context. The focus should be on the ratio of the drum's radius to the axle's radius, which directly illustrates the mechanical advantage provided by the system.