An ultrasound imaging system is equipped with two square transducers. One operates a...

An ultrasound imaging system is equipped with two square transducers. One operates at 5 MHz, and the other one operates at 12 MHz. The 5-MHz transducer is 2.0 cm by 2.0 cm and the 12-MHz one is 0.4 cm by 0.4 cm. The imaging system is tested in a medium having a speed of sound of 1,560 m/s at both frequencies.

(a) What are the absorption coefficients of the medium at the frequencies of the transducers?

(b) What ranges are considered as far field for each transducer?