Period, Frequency, Wavelength, and Propagation Speed:

At times it is simpler to talk about a wave's period instead of its frequency. The period T (i.e., in seconds) of a sine wave is the reciprocal of the frequency f (i.e., in hertz). Mathematically, the formulas below hold:

f = 1/T = T^-1

T = 1/f = f^-1

When a wave consists of a frequency of 1 Hz, its period is 1 s. When the frequency is one cycle per minute (1/60 Hz), the period is 60 s. When the frequency is one cycle per hour (1⁄3600 Hz), the period is 3600 s, or 60 minutes.

The period of a wave is associated to the wavelength λ (in meters) and the propagation speed c (in meters per second) as follows: Wavelength equals speed times period. Mathematically:

λ = cT

This gives mount to other formulas:

λ = c/f

c = fλ

c = λ/T