Understanding Rotational Speed
Rotational speed refers to the number of complete turns a rotating object makes per unit of time. It is a fundamental concept in mechanical and electrical engineering.
Introduction & History
The measurement of rotational speed became crucial with the development of the steam engine and later internal combustion engines. The tachometer, an instrument for measuring rotational speed, was invented in the early 19th century.
Key Units
Revolutions per minute (rpm)
The number of complete turns in one minute, commonly used for engines and mechanical systems.
Radians per second (rad/s)
The SI derived unit of angular velocity, representing the angle in radians through which an object rotates in one second.
Hertz (Hz)
Revolutions per second, used for high-speed rotations.
Practical Applications
Automotive engineering
Industrial machinery
Aerospace
Electric motors
Turbines
Key Formula
Linear Speed from Rotational Speed
The linear speed (v) of a point on a rotating object is equal to the product of the distance from the axis of rotation (r) and the angular velocity (ω) in radians per second.