The echo-receiver of a sonar attached to a ship, receives the echo from the bottom of sea 4 seconds after the ultrasonic waves were sent into the sea. If the speed of sound in water is 1500 m/s, then what is the depth of the sea?

The echo-receiver of a sonar attached to a ship, receives the echo from the bottom of sea 4 seconds after the ultrasonic waves were sent into the sea. If the speed of sound in water is 1500 m/s, then what is the depth of the sea? Correct Answer <p>3000 m</p>

Concept:

SONAR

• It a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water
• SONAR stands for ‘Sound Navigation and Ranging’. SONAR is based on the principle of echo.
• If we shout or clap near a suitable reflecting object such as a tall building or a mountain, we will hear the same sound again a little later.
• This sound which we hear is called an echo.
• The reflection of sound means bouncing back after striking a surface, phenomena much similar to reflection of light. 

Important Points

• The sound whose frequency is more than 20,000 Hz is known as ultrasound. 
• SONAR Sends Ultrasound to the bottom. 
• This has many applications in science and technology.