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 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 frequently in s. 1 inch per second is equivalent to: 1 metre per second ≈ 39.370079 inches per second (approximately)<br> 1 foot per second = 12 inches per second (exactly)<br> 1 mile per hour = 17.6 inches per second (exactly)<br> 1 kilometre per hour ≈ 10.936133 inches per second (approximately) In magnetic