In flight bats emit a range of (ultrasonic) frequencies of sound and use the reflected sound signals for locating the insects they eat. A typical frequency is 45,000 Hz, and the speed of the ultrasound in air is about 344 m/sec. What is the wavelength of the ultrasound in air? Under water dolphins emit sound to communicate. A typical frequency of a bottle-nosed dolphin is about 90,000 Hz. If the wavelength of this sound in water is found to be 1.7 cm, what must be the speed of sound in this water?