Answer:
The relationship between the frequency of a wave and the wavelength is an inverse relationship, therefore, if the wavelength of a wave increases and the velocity of the wave stays the same, the frequency of the wave decreases.
An example is the ocean wave, if the distance between successive wave crests, which is the wavelength, 'λ', of the wave, increases, while the velocity, 'v', of the wave coming to shore remains the same, the number of wave crest arriving at the beach in a given period of time, which is the frequency of the wave, 'f', decreases according to the following equation;
f = v/λ
Explanation:
