What does machine efficiency measure?

Machine efficiency is a measure of how effectively a machine converts input energy into useful output work. It is often expressed as a percentage and is calculated by dividing the useful work output by the total input energy, then multiplying by 100. This metric is crucial because it indicates how well a machine performs its intended task relative to the energy it consumes. A higher efficiency means that more of the input energy is being used for productive work rather than being wasted in forms such as heat, noise, or vibrations.

This concept highlights that while a machine might operate at a certain speed or have durable components, those factors alone do not define its efficiency. Instead, the focus on the input-to-output energy ratio allows for a clear understanding of the machine's overall performance and effectiveness in achieving its purpose.