Question

As a ship approaches a Cliff, it's siten is sounded and the echoe is heard in the ship after 12secs. 2/mins later the sires is sounded again and the echoe is heard 8secs later,if the speed of sound in air is 340m/s culcalate the velocity at which the ship is approaching the Cliff ?

Answer 1

Answer:

v = speed of sound

t= time

d = displacement

In case (i) :

We know v = 2d / t

Given , v = 340

t = 12 s

Substituting values :

340 = 2d / 12

340 × 12/2 = d

d = 2040m

In case (ii):

Given v = 340

t= 8s

Substituting values in v = 2d / t :

340 = 2d / 8

340 × 8 / 2 = d

d = 1360m

Now, 2040 – 1360 = 680m

So the ship travelled 680 m between the time in which 2 sirens were blown. Also time is given as 2min or 120seconds.

Velocity = displacement / time

Velocity = 680/12

Velocity of ship = 5.6 m/ s

Hope it helped