Question

A drop of water fell on the surface of a still water,so a 120 wave ripples are produced during half minute.If the radius of external circle is 3m, the speed of prpagation of wave equals.....?

Answer 1

Distance between waves:

$$d=\frac{3}{120}=0.025\ m=2.5\ cm$$

Ths speed of propagation of wave equals

$$v=\frac{d}{t}=\frac{2.5}{0.5}=5\frac{cm}{min}$$