Please show work a. Sonar can detect small objects such as fish that are of a si
ID: 2027973 • Letter: P
Question
Please show worka. Sonar can detect small objects such as fish that are of a size approximately that of one wavelength. If an angler’s sonar emits a pulse at a frequency of 10 kHz, and the speed of sound in water is 1480 m/s, what is the smallest size fish she can detect?
b. A 3.00 m long organ pipe is open at one end and closed at the other. Its fundamental tone has the wavelength:
c. A train station bell gives off a fundamental tone of 500 Hz as the train approaches the station at 25 m/s. If the speed of sound is 335 m/s, what will be the apparent frequency of the bell to an observer riding the train?
Explanation / Answer
a) wavelength = v / f = 1480 / 10000 = .148 m (about 1/2 foot) b) pipe has node at one end and antinode at other so it is 1/4 wavelength long at the fundamental frequency wavelength = 12 m c) f = f0 (V + v/ V for stationary source and moving observer f = 500 (335 + 25) / 335 = 537 Hz