Frequency German physicist Heinrich Hertz. One hertz means that an event repeats once per second. If a TV has a refresh rate of 1 hertz the TV's screen will change (or refresh) its picture once a second. A previous name for this unit was cycles per second (cps). The SI unit for period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz. As a matter of convenience, longer and slower waves, such as ocean surface waves, tend to be described by wave period rather
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