Final answer:
RPM stands for revolutions per minute, a unit used to measure rotational speed. It's converted to radians per second for use in physics formulas to calculate angular velocity and related quantities like centripetal acceleration.
Step-by-step explanation:
The term RPM in formulas stands for revolutions per minute, which is a measure of the frequency of rotation. To calculate related physical quantities, we often need to convert RPM to radians per second to obtain the angular velocity (usually represented by the Greek letter omega, ω). For instance, with the given radius r, we can determine the centripetal acceleration (ac) using the formula ac = rω². This conversion and calculation are important in contexts such as comparing engine speeds, determining wheel rotation in a race, or calculating rotational acceleration.