How do the following use echoes? 1. army, 2. geologists, 3. fisherm

1.	How do the following use echoes? 1. army, 2. geologists, 3. fishermen
Answer» (i) army : Echoes are used by army to locate the gun position of enemy. Radar an instrument is used to locate an enemy air-craft ship. (ii) geologists : Echoes are used by geologists for mineral prospecting. (iii) fishermen : for locating fishes ultrasonic waves are sent into water. If these vibrations strike a fish, they are reflected back to the receivers. The time for hearing the echoes recorded. The position of fish is calculated by d = v × t/2 using vel. of sound in water as 1450ms^-1.

How do the following use echoes? 1. army, 2. geologists, 3. fishermen

Answer»

(i) army : Echoes are used by army to locate the gun position of enemy. Radar an instrument is used to locate an enemy air-craft ship.

(ii) geologists : Echoes are used by geologists for mineral prospecting.

(iii) fishermen : for locating fishes ultrasonic waves are sent into water. If these vibrations strike a fish, they are reflected back to the receivers. The time for hearing the echoes recorded. The position of fish is calculated by d = v × t/2 using vel. of sound in water as 1450ms^-1.

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