Frequency of a wave is the number of times something happens divided by the time it takes. A frequency is messured in hertz one hertz is equal to one wave per second. a frequency is also found by taking 1 over the period a period is the time needed for one complete cycle of vibration to pass a given point. As the frequency of a wave increases, the period of the wave decreases. The Period equals the Total time divided by the Number of cycles. An example of a period is The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle. FUN FACT! The period for the minute hand on a clock is 3600 second, it takes the minute hand 3600 seconds to complete one cycle around the clock.