Answer Happy

An ultrasound wave of frequency 5 MHz and intensity 11 = 1.00 x 10-9 W/mat location 1 shown in the figure below travels in tissue of acoustic impedance 1.68 x 106 kg/(s-m2). The half-length of the sound at 5 MHz in tissue is 1.2 cm. The wave travels a distance d and suffers attenuation before reaching the muscle-bone interface at the location 2.6 pts muscle bone I 12 I ref Izref d 1 I. In your words, define the half-intensity length. II. Calculate the intensity of sound, I2, after it travels the distance d =2.4 cm equal to two half-lengths in tissue and reaches the location 2. III. Location 2 is a muscle bone interface with acoustic impedance of 7.80 x 106 kg/(s- m2). Calculate the intensity of the reflected beam at 2, 12ref- IV. The reflected beam now travels back through the tissue and arrives at 1. Calculate the intensity of the reflected beam at 1. V. Calculate the percent decrease in intensity in the beam during the round trip. Comment about the percent decrease.