# Ultrasound Calculations

The table provides the data for the acoustic impedance and absorption coefficients for muscle and bone.

A parallel beam of ultrasound of intensity $I_0$ enters the muscle of thickness 3.0 cm as shown. The ultrasound is then reflected at the tissue boundary and returns to the surface of the muscle.

Calculate the intensity, in terms of $I_0$, that is received when the ultrasound returns back to the surface of the muscle.

There are three important parts to solve this problem. The first part would be the attenuation of intensity inside the muscle. The second part would be the reflection of ultrasound at the muscle-bone boundary. The last part would be the intensity attenuation inside the muscle back to the surface.

$I=I_0 e^{-21 times 0.03}$