Consider two organ pipes. The first pipe is open at both ends and it\'s 1.161 m
ID: 1481520 • Letter: C
Question
Consider two organ pipes. The first pipe is open at both ends and it's 1.161 m long. The second pipe is open at one end and closed at the other end; it's 1.776 m long. When both pipes are played together, the first, overtone the lowest harmonic above the fundamental frequency of the second pipe produces beats against the fundamental harmonic of the first pipe. What is the frequency of these beats? Take the sound speed in air to be 341 m/s. Answer in units of Hz. While waiting for Stan Speedy to arrive on a late passenger train. Kathy Kool notices beats occurring as a result of two trains blowing their whistles simultaneously. One train is at rest and the other is approaching her at a speed of 26.1 km/h. Assume that both whistles have the same frequency and that the speed of sound is 344 m/s. If Kathy hears beat frequency at 5.69 Hz, what is the frequency of the whistles? Answer in units of Hz.Explanation / Answer
the formula for fundamental frequency is
f = v/2L for open at both ends
f = v/4L for open at one end
f3 = 3v/4L_2
f1= v/ 2L_1
beat frequency is
delf = f3- f1 mod
= 3v/ 4L_2 - v/2 L_1
= 3(341)/ 4 (1.776) - 341/ 2 ( 1.161)
= mod 144 -146.85
beat frequency is 2.85 Hz
As per guide lines I worked first problem