3. A narrow tube contains two sections filled with different media: the first 250m is air and the next 300m is fresh water. A sound pulse starts at one end of the tube and travels straight through both sections to a detector at the far end. The total time taken for the pulse to reach the detector is 0.60s. The speed of sound in water is 1500ms−1.
Use this information to answer the following parts.
(a) Calculate the time taken by the sound pulse to travel through the water section.
(b) Hence determine the time taken to cross the air section.
(c) Using your result from part (b), compute the speed of sound in air for the conditions inside the tube.
(d) Compare the value obtained in part (c) with the commonly accepted speed of sound in air (343ms−1). State whether your value is higher or lower and suggest one physical factor that could account for the difference.