What is a common measurement of speed for a rotating pulley?

A common measurement of speed for a rotating pulley is revolutions per minute (RPM). This unit quantifies how many complete rotations the pulley makes in one minute, effectively indicating its rotational speed. RPM is particularly useful in mechanical and engineering contexts, as it allows for easy comparison of the operational speeds of different pulleys or motors.

Using RPM as a measurement is advantageous because it directly relates to the performance and efficiency of machinery. For example, in an engine or conveyor system, knowing the RPM helps in understanding how quickly parts are moving, which is crucial for both design and operational parameters.

In contrast, while linear meters per second can measure speed, it specifically applies to linear motion rather than rotational motion. Torque measures rotational force and would not directly indicate speed. Lastly, angle in degrees provides information about the position of a rotation but does not measure speed or the rate at which the pulley is rotating. Therefore, revolutions per minute remains the most appropriate and widely used unit for this purpose.