An echo-sounder in a trawler (fishing boat) receives an echo from a shoal of fish 0.4 s after it was sent. If the speed of sound in water is 1500 m/s, how deep is the shoal ?
(a) 150 m
(b) 300 m
(c) 600 m
(d) 7500 m

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Solution

Time taken to list the sent signal is 0.4 s.
Speed of sound in water is 1,500 m/s.
So,
$= \frac{1500 \times 0.4}{2} = 300 m$
Ans: (b) 300 m.

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An echo-sounder in a trawler (fishing boat) receives an echo from a shoal of fish 0.4 s after it was sent. If the speed of sound in water is 1500 m/s, how deep is the shoal ? (a) 150 m (b) 300 m (c) 600 m (d) 7500 m

Time taken to list the sent signal is 0.4 s. Speed of sound in water is 1,500 m/s. So, =1500×0.42=300 m Ans: (b) 300 m.

An echo-sounder in a trawler (fishing boat) receives an echo from a shoal of fish 0.4 s after it was sent. If the speed of sound in water is 1500 m/s, how deep is the shoal ?
(a) 150 m
(b) 300 m
(c) 600 m
(d) 7500 m

Time taken to list the sent signal is 0.4 s.
Speed of sound in water is 1,500 m/s.
So,
$= \frac{1500 \times 0.4}{2} = 300 m$
Ans: (b) 300 m.