The method to choose depends on what information you have, and
on what you can measure. Here are a few possible methods:
-- Measure the period. Start your clock when one peak
of the wave passes you. Stop the clock when the next
peak passes you. The time between the two peaks is
the wave's period.
-- Divide the wave's wavelength by its speed. That quotient
is the wave's period.
-- Use an electronic frequency meter to measure the wave's
frequency. Then take its reciprocal (divide ' 1 ' by it). The
result is the wave's period.
