a. Find the exact length of the second pipe B. 3 meters away from both pipes, you measure the sound level to be 79db. How many pipes would need to be playing to produce a level of 120db? 25. Two pipes from an organ are played at the same time to create a beat frequency. The first pipe is 3.3meters tall and closed on one end. The second pipe is open on both ends and is roughly triple your height|(you are 1.5 meters tall). When both pipes play together, they produce a beat frequency of 13 Hz.

The beat frequency is defined as the difference in the frequency produced by two sources when played simultaneously. The frequency of sound produced by a one side closed pipe is given by the formula f1=v4L , where v=330 m/s is the speed of sound in air and L=3.3 m is the length . The frequency of sound produced by a both sides opened pipe is given by the formula f2=v2L , where v=330 m/s is the speed of sound in air and L is the length . Calculate the frequency of first pipe by using the formula f1=v4L , where v=330 m/s is the speed of sound in air and L=3.3 m is the length . f1=v4L=330 m/s4×3.3 m=25 HzCalculate the frequency of second pipe by using the relation f2=f1+f , where f1=25 Hz is the frequency from the pipe and f=13 Hz is the beat frequency. f2=f1+f=25 Hz+13 Hz=38 HzCalculate the length of the second pipe by using the formula f2=v2L , where v=330 m/s is the speed of sound in air and f2=38 Hz is the frequency of the second pipe . f2=v2LL=v2f2=330 m/s2×38 Hz≈4.34 mCalculate the number of pipes by using the relation n2=n1I2I1 , where n1=2 is the number of pipes , I2=120 dB is the new intensity and I1=79 dB is the initial intensity. n2=n1I2I1=2×120 dB79 dB≈3The length of the second pipe is L≈4.34 m . The number of pipes is 3.