A string with a mass per length of 2.00 g/m is stretched with a force of 120 N between two points that are 0.400 m apart. The fundamental frequency of the stretched string is in tune with the frequency of the second mode of an organ pipe filled with air at -20°C and open at both ends. The speed of sound in air at 0°C is 331 m/s. What is the length of the organ pipe?
A) 1.325 m
B) 1.660 m
C) 2.650 m
D) 3.320 m
