Velocity and wavelength are directly proportional when frequency is kept constant.
<h3><u>Explanation;</u></h3>
<em><u>Frequency of a wave is the number of complete oscillations made by a given wave in one second. </u></em>
<em><u>Wavelength on the other hand, is the distance between two successful crests or troughs in a transverse wave or two successful rarefactions or compressions in a longitudinal waves.</u></em>
<em><u>The speed of a wave is given by the product of the frequency of a wave and the wavelength.</u></em>
<em><u>Speed = Frequency × wavelength, </u></em>
<em><u>Therefore, if frequency is kept constant, then the speed of a wave is directly proportional to the wavelength, such that an increase in wavelength increases the speed of the wave and vice versa.</u></em>