24.3b ON10 P42 Q10 Reflection Coefficient at Boundaries | A2 Medical Physics | CAIE A Level Physics

Example - 9702/42/O/N/10: (a)(i) State what is meant by the acoustic impedance of a medium. #9702w10p42 #Lv2 #A2reflectionImpedanceP4 (ii) Data for some media are given in Fig. 10.1. Use data from Fig. 10.1 to calculate a value for the density of bone. The media have acoustic impedances of Z1 and Z2. The transmitted intensity of the ultrasound beam is IT and the reflected intensity is IR. (b) A parallel beam of ultrasound has intensity I. It is incident at right-angles to a boundary between two media, as shown in Fig. 10.2. (i) State the relation between I, IT and IR. (ii) The reflection coefficient a is given by the expression below. Use data from Fig. 10.1 to determine the reflection coefficient a for a boundary between 1. gel an soft tissue, 2. air and soft tissue. (c) By reference to your answers in (b)(ii), explain the use of a gel on the surface of skin during ultrasound diagnosis. #A2MedicalPhysics Applications Playlist:    • Ch24 Medical Physics | CAIE 9702 A2 Physics   #A2ultrasoundWaves Playlist    • [ARCHIVED] A2 Waves: Ultrasound | CAIE 970...   Instagram Pocket Guide (  / etphysics  ) More Resources (https://9702-physics.blogspot.com/) Support us! (  / etphysics  ) Tuition/Tutoring inquiries: Email: suitlin@gmail.com Whatsapp: https://wa.me/60126679171 9702_w10_qp42 October/November 2010 #CambridgeALevelPhysics