Frequency
(Reguidit frae Period (pheesics))
Frequency is the nummer o occurrences o a repeatin event per unit time. It is an aa referred tae as temporal frequency, which emphasizes the contrast tae spatial frequency an angular frequency. The period is the duration o ane cycle in a repeatin event, so the period is the reciprocal o the frequency. For example, if a newborn baby's heart beats at a frequency o 120 times a minute, its period (the interval atween beats) is hauf a seicont.
Three cyclically flashin lichts, frae lawest frequency (tap) tae heichest frequency (bottom). f is the frequency in hertz (Hz), meanin the nummer o cycles per seicont. T is the period in seiconts (s), meanin the nummer o seiconts per cycle. T an f are reciprocals.