sound

A tube of length L contains a gas at temperature T. One end of the tube is closed and the other end is open. A small speaker producing sound of variable frequency is placed at the open end. The frequency of the speaker is increased until the sound from the tube first becomes very loud. With further increase of the frequency, the loudness

decreases but then gets very loud again at still high frequencies. The lowest frequency at which the sound is very loud is f0, is the ratio of its heat capacities, R is the ideal gas constant and M is the molar mass of the gas.

Ques.
1]The absolute temperature of the gas is
2]If the fundamental frequency at 27°C in a column of methane is 1100 Hz in that closed tube of length L = 0.1 m, the ratio of heat capacities is (Molar mass of methane = 16 g/mole, )
3]The speed of sound in this tube at temperature T = 27°C is