Q3 of 8 Page 23

A sound signal from a ship floating on water, hits a rock at the bottom of the sea and comes back to the ship after 4 s. Calculate the distance of the rock from the surface of water. The speed of sound in water is estimated to be 1500 m/s.

Info. from the question:

Speed of sound = 1500 m⁄s


Time taken for to and fro round = 4 s

The time given in the question is of complete round of sound wave that is sending and receiving it back, so if we take distance between ship and rock = d then,

the total distance travelled = 2d

2d = speed× time

2d = 1500× 4

2d = 6000

d = 3000 m.[T1]

Hence, the distance between rock and ship = 3000 m.

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