A diagnostic device emits ultrasound of frequency 3MHz into human soft tissue where the speed of sound is 1540m/s.
(i) Calculate the wavelength of the ultrasound in the tissue.
(ii) If the device can distinguish details as small as half the wavelength, determine the minimum size of an object that can be resolved.
(iii) Explain why using an even higher frequency might improve resolution but could introduce practical limitations in medical imaging.