An oceanographic buoy emits an ultrasonic pulse of frequency 40kHz straight downwards into sea water and detects the reflected signal.
(a) The echo is received 1.5s after emission. If the speed of sound in the water at the site is 1500ms−1, calculate the depth of the sea bed directly below the buoy.
(b) For the same water conditions, determine the wavelength of the 40kHz ultrasonic wave in the sea.