2. Explain why the velocity of sound increases as the temperature of the gas increases. 3. Does water vapor in the air cause the speed of sound to be greater or less than the speed of sound in dry air? Explain. 4. Derive (7) from (2) and derive (8) from (3). 5. The ideal gas analysis for the root-mean-square velocity of the molecules gives the velocity as. v = VM , where -y is the ratio of heat capacities, R is the Universal Gas constant, y- is the absolute temperature of the gas, and M is the molecular mass of the molecules. Use this expression to calculate the speed of sound in air for the trial when the 385 Hz tuning fork was used. Compare this value with the values obtained using the resonance tube apparatus. \fSv = k(ST ). 8) theory\fV = 331.4+0.67 theory (3