☆●In a submarine equipped with SONAR, the time interval between generation of wave and reception of its echo after reflection from the enemy submarine is found to be 40s. If the speed of ultrasonic waves in sea water is 1450m/s, then the distance of * a)38Km b) 48Km c) 29Km d) 68Km please answer it fast
Answers
Distance of the submarine from enemy submarine is 29 km [Option.c]
Step-by-step explanation:
We have :-
→ Time taken by the wave (t) = 40 s
→ Speed of the wave (v) = 1450 m/s
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If 'd' is the distance of the submarine from the enemy submarine, then total distance travelled by the wave in time interval 't' is '2d' .
Speed = Distance/Time
⇒ v = 2d/t
⇒ vt = 2d
⇒ d = vt/2
Putting values in obtained formula :-
d = vt/2
⇒ d = (1450 × 40)/2
⇒ d = 1450 × 20
⇒ d = 29000 m
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Finally let's convert the obtained distance from 'm' to 'km' .
⇒ 1 m = 0.001 km
⇒ 29000 m = 29000(0.001) km
⇒ 29 km
Let the distance between the ship and the enemy submarine beS.
Speed of sound in water =1450m/s
Time lag between transmission and reception of Sonar waves =77s
In this time lag, sound waves travel a distance which is twice the distance between the ship and the submarine (2S).
Time taken for the sound to reach the submarine =21×77=38.5s
Distance between the ship and the submarine, S=1450×38.5=55825m=55.8km