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 works by emitting sound pulses and measuring the time it takes for the echo to return after bouncing off an object. - The speed of sound in water is known, so the distance can be calculated from the travel time. - Ultrasonic waves (frequencies above the human hearing range, typically >20 kHz) are preferred in SON‐ AR for several reasons, including better directionality, less attenuation over typical ranges compared to higher frequencies, and superior resolution compared to lower (infrasonic or audible) frequencies for object detection.