Figure 2. A-scan X WAScan File Options Scale View Modi About TM-mode 1 MHz Sound Velocity [m/s) |2690.0 FFT Filter Stop Full Time Depth HF Amp HF+AMP AScan B-mode Input Voltage [ Reflection 0.5- 0 0 - -05- 8- 100 120 20 60 Depth [mm] TGC [dB] 35- 30 - 25 - 20 - 15- 10 - -. ... - . . .. 100 120 3- 20 80 Amplitude Gain Output Cursor1 Curso:2 Difference 0.500V 10 CB 30 CB 0.5 mm 8.6 mm 8.0 mm7. a) Write an equation which denes the acoustic impedance of a tissue. Explain the quantities which appear in this equation. b) Give examples of the values (including units) of the acoustic impedance for three different tissues. 0) Find a percentage of the ultrasound intensity reected from the interface separating muscle and bone (use the table for the acoustic impedance). . . Speed of sound Acoustic Impedance Materials / Tissues vs m/S 2 kg \"11123) Air 344 400 Acrylic (polyacrylate) plastic 2690 3,200,000 Water 1 500 1,500,000 Muscle 1570 1,650,000 Fat 1 440 1,300,000 Bone 3500 7,800,000 Soft tissue (average value) 1540 1,600,000 6. Find the velocity of ultrasound in a tissue where a S-MHz frequency ultrasound pulse has a 480-pm wavelength (1 mm = 10'6 m). What type of tissue is it? (Include units) 10. An A-scan is shown in Figure 2 on page 4. What is the time delay between the initial pulse and the first echo which produce this A-scan? (Include units)