X-rays travel at a speed of _________`ms^(-1)`.

gamma-rays travel with the speed of _________.

In a gas sound travels at a speed of 315 ms^(-1) at NTP, If R=8.3J mol^(-1) K^(-1) identify the gas.

At 27^(@)C a gas contains 10 molecules travelling with a speed of 4 ms^(-1) , 20 molecules travelling with a speed of 5 m s^(-1) and 40 molecules travelling with a speed of 8 m s^(-1) . Calculate the average speed, root mean square speed and most probable speed of the gas at 27^(@)C .

What will be the frequency of sound having 0.20 m as its wavelength, when it travels with a speed of 331 ms^(-1) ?