A sound wave travelling through air has a wavelength of 0.85m and the speed of sound in air is 340m/s.
(i) Calculate the frequency of the wave in air.
(ii) Determine the time period of the wave in air.
(iii) The same wave enters water where the speed of sound is 1500m/s while its frequency remains unchanged. Find (a) its wavelength and (b) its time period in water.