Question

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR, the time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is found to be 77.0 s. What is the distance of the enemy submarine? (Speed of sound in water = 1450 m s¯¹).

Answer 1

Given: Time delay between generation of a probe wave and the reception of its echo after reflection from an enemy submarine is 77.0 s and the speed of sound in water is 1450 m/s.

Distance between the ship and the submarine is given as,

D=v× t 2

Where, speed of sound in water is v and time lag between generation of probe wave and its reception is t.

By substituting the given values in the above formula, we get

D=1450× 77 2 =55825 m =55.8 km

Thus, the distance between the ship and the submarine is 55.8 km.