How did sonar contribute to discoveries about the ocean bottom

Sonar can be used to measure the depth of the ocean bottom

Explanation:

Sonar is a device which uses ultrasound waves to measure the depth of the ocean.

When a sonar is used on a boat, the device emits an ultrasound wave. This wave travels from the boat to the bottom of the ocean, then it is reflected and travels back to the boat. By knowing the speed of the sound wave in water, and by measuring the time it takes for the wave to come back, one can measure the depth of the ocean. In fact:

- v is the speed of the sound wave in water (approximately 1500 m/s)

- t is the total time it takes for the wave to leave the sonar and come back

- d is the distance between the boat and the bottom of the ocean

The sound wave takes a time t to cover twice the distance between the boat and the bottom of the ocean (2d), so we have

So we can calculate the depth of the ocean:

wavelength variability is the right one