Hertz radians per second. Thus a disc rotating at 60 revolutions per minute (rpm) is said to be rotating at either 2 rad/s "or" 1 Hz, where the former measures the angular velocity and the latter reflects the number of "complete" revolutions per second. The conversion between a frequency "f" measured in hertz and an angular velocity "ω" measured in radians per second is The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1930. It was adopted by
Inch per second tape sound recording, magnetic tape speed is often quoted in inches per second (abbreviated "ips"). Also computer mice sensitivity is also often referred to in inches per second (abbreviated as "ips") along with g force. In rotorcraft health monitoring, rotor and shaft induced vibration levels are often quoted in inches per second. Inch per second The inch per second is a unit of speed or velocity. It expresses the distance in inches ("in") traveled or displaced, divided by time in seconds ("s", or "sec"). The equivalent SI unit is the metre per second. Abbreviations include in/s, in/sec, ips, and less