________________ refers to the superposing of two or more coherent waves to produce regions of maxima and minima in space, according to the principle of superposition.
Pihu and Aayu are running on a circular track of diameter 28m. Speed of Pihu is 48 m/s and that of Aayu is 40 m/s. They start from the same point at the same time in the same direction. When will they meet again for the first time?