When calculating the efficiency of a machine, what is the typical unit of measurement for output and input work?

The efficiency of a machine is defined as the ratio of useful output work to the input work, often expressed as a percentage. Both output work and input work are measured in Joules, which is the standard unit of energy in the International System of Units (SI).

Joules quantify the amount of work done when a force of one Newton is applied over a distance of one meter. This direct relationship makes it straightforward to compare the work being put into a machine against the useful work being produced. Thus, when assessing a machine's performance, utilizing Joules for both input and output provides a clear and consistent framework for evaluating efficiency.

Other units, such as Watts, Newtons, and Meters, do not serve the same purpose in this specific context. Watts measure power (the rate of doing work), Newtons are a unit of force, and Meters measure distance. Therefore, Joules is the appropriate and relevant unit for calculating the efficiency of machines.