A tube that is open at both ends is filled with an unknown gas. The tube is 190 cm long and 3 cm in diameter. By using different tuning forks it is found that resonances can be excited at frequencies of 315 Hz, 420 Hz and 525 Hz, and at no other frequencies in between. We now the speed of sound in this gas is 399 m/s.
Can you determine the amplitude of the wave? If so, what is it? If not, why not?