A sample of synthetic polymer gel used to calibrate medical ultrasound phantoms has a volume of 4.5 cm3 and a mass of 4.95 g. The speed of ultrasound in this gel sample is 1540 m s-1.
What is the acoustic impedance of the polymer gel?
1.69×103 kg m−2 s−11.69 \times 10^3\text{ kg m}^{-2}\text{ s}^{-1}1.69×103 kg m−2 s−1
1.69×104 kg m−2 s−11.69 \times 10^4\text{ kg m}^{-2}\text{ s}^{-1}1.69×104 kg m−2 s−1
1.69×106 kg m−2 s−11.69 \times 10^6\text{ kg m}^{-2}\text{ s}^{-1}1.69×106 kg m−2 s−1
1.69×109 kg m−2 s−11.69 \times 10^9\text{ kg m}^{-2}\text{ s}^{-1}1.69×109 kg m−2 s−1
