We're doing a lab to determine the ratio of specific heat of nitrogen gas (r) by using the equation v=ROOT(rRT/M), where v is the speed of sound in pure nitrogen gas, R being 8.314J/molK, T being 298K (room temp), M of nitrogen being 0.028kg/mol. In the experiment, the function generator was connected to the speaker, whereas the oscilloscope was connected with the microphone inside the gas tube. when the microphone was moved away from the speaker, the graph displayed on the oscilloscope (voltage vs. time) only changes in amplitude (thus the voltage), but the nodes stay where they are. the pressure in the gas tube was 1.7 kpa, the frequency of wave generated by function generator was 2 kHz. I understand that we need to determine speed of sound by v=f(lambda), frequency could be determined from f=1/period, but what about lambda? is the calculation of lambda related with the d between the microphone and the speaker? if so, how?