Frequency
 The frequency of the wave is related to the wavelength. The frequency is the number of cycles per second. Frequency can be measured in two ways by given units of time, most common in Hertz (per second). A high frequency has more crests per second and a low frequency it has less crest per second. There are two equations that are used to find frequency. f = V / (velocity over time) f = 1 / T (one over time) Wavelength as you can tell by the equations is related to frequency. A way to distinguish high and low frequencies is by their wavelengths. The longer the wave, the lower the frequency conversely, the shorter the wave, the higher the frequency. The higher the frequency of the wave, the more danger it will have on humans. There are some waves that are harmful to humans if exposed with too much. For example, Ultra Violet waves (waves from the sun) can cause the skin to be damaged or burned with too much exposure. Limited damage can be healed, however, extreme UV waves exposed to a human body for long periods of time, can become deadly. For example, cases such as cancer can develop. [an error occurred while processing this directive]