SONAR is a device that is used to measure the distance of underwater objects by a ship. Which of the following types of waves does it use for this purpose?

SONAR (Sound Navigation and Ranging) is a specialized device used by ships and submarines to detect and measure the distance, direction, and speed of underwater objects [1]. It operates by emitting ultrasonic waves, which are sound waves with frequencies exceeding the human hearing limit of 20 kHz. These waves are generated by a transmitter and travel through the water until they strike an object or the seabed. Upon impact, the waves reflect as an echo, which is then captured by a receiver [1]. By calculating the time interval between the transmission and reception of the pulse, and knowing the speed of sound in water, the distance to the object is determined. While some passive sonar systems listen for various frequencies, active ranging specifically utilizes ultrasonic waves because they can travel long distances in water with minimal divergence.

Sources

1. [1] https://oceanservice.noaa.gov/facts/sonar.html