Period is measured in seconds. All waves, including sound waves and electromagnetic waves, follow this equation. It should be noted that some particular waves have their own specific speeds ...

For example, in AM radio, the voltage (amplitude) of a carrier with a fixed center frequency (the station's channel) is varied (modulated) by the analog audio signal.

A tuning fork has a frequency of 440 Hz ... Use the information given in the question to select the appropriate equation to use.