The period of an 8000 Hz sine wave is 0.125 milliseconds. (1/8000)
The period is 1 millisecond.
The period of a 15MHz sine wave is 1 / 15MHz, or 0.066667 us, or 66 2/3 ns.
Wave speed is simply frequency multiplied by wavelength. 1.2m * 250Hz = 300m/s
The period of 1GHz is 1 ns. The waveform is irrelevant.
If you have a 5Hz sine wave, the period is 200mS--a fifth of a second.
It is 1/810,000 = 0.00000123456790123456790... recurring.
1 divided by 100,000,000.00 in sec
the length of time it takes to complete one cycle