Answer:
Speed of he wave is equal to 40 m/sec
Step-by-step explanation:
We have given distance between adjacent crest is 48 m
Distance between adjacent crest is equal to half of the of the wavelength
So


Time period is given T = 2.4 sec
So frequency

We have to find the speed of wave
Velocity is given by

So speed of the wave will be equal to 40 m/sec