Question

The sound of an exploison on the surface of lake is heard by a boatman 100m away and a diver 100m below the point of exploison. Of the two persons mentioned who would hear tbr sound first and why

Answer 1

Ans

For the boatman above the surface of water...

speed of sound in air = 344 m/s

distance covered = 100 m

time taken by sound = t sec

velocity = distance / time

344 = 100 / t

t = 100 / 344

t = 0.29 sec

Now, for the man below the surface of water

speed of sound in water = 1533 m/s

distance covered = 100 m

time taken = t

But velocity = distance / time

1533 = 100 / t

t = 100 / 1533

t = 0.06 sec

So , the man under the water hear the sound of the explosion first....