How do you calculate the mechanical advantage of a machine that requires 5N of input force to produce 25N of output force?

To determine the mechanical advantage of a machine, you assess how effectively it amplifies your input force. The ratio of output force to input force is a straightforward and effective way to calculate this advantage. By taking the output force (25N) and dividing it by the input force (5N), you get a mechanical advantage of 5. This means that the machine allows you to exert a smaller input force to achieve a greater output force, making it easier to perform work.

Other options may refer to aspects of how machines operate, but they do not directly provide the mechanical advantage calculation. For instance, designing a formula or measuring distances moved relates more to different mechanical principles rather than focusing specifically on the ratio of forces, which is the crux of mechanical advantage. Using the work done could involve different calculations or context that might not directly yield the mechanical advantage by itself. Hence, the best choice is to take the ratio of output to input forces.