In: Physics
A 24 cm long wire with a linear density of 31.5 g/m passes across the open end of a 102 cm long open-closed tube of air. If the wire, which is fixed at both ends, vibrates at its fundamental frequency, the sound wave it generates excites the second vibrational mode of the tube of air. Assume the speed of sound is 340 m/s. What is the fundamental frequency of the wire? What is the wave speed on the wire?
the frequency in the tube is
f3open-closed tube = 3v/ 4Ltube
= (3)(340m/s) / (4)(102*10-2 m)
= 250 Hz
frequency in wire f1wire = vwire/ 2Lwire
250 Hz = (1/2Lwire ) ?Ts/?
Ts = ( 250 Hz)2 ( 2Lwie)2 ?
= ( 250 Hz)2( 2 * 0.24m)2( 0.0315 kg/m)
= 226.8 N