Diatomic molecules like hydrogen have energies due to both translational as well as rotational motion. From the equation in kinetic theory pV =2/3 E  , E is

(a) The total energy per unit volume

(b) Only the translational part of energy because rotational energy is very small compared to the translational energy

(c) Only the translational part of the energy because during collisions with the wall pressure relates to change in linear momentum

(d) The translational part of the energy because rotational energies of molecules can be of either sign and its average over all the molecules is zero

The root mean square speed of molecules of a gas is 1260 m/s. The average speed of the gas molecules is

A block rests on an inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between block and the plane is 0.8. If the frictional force on the block is 10 N, then mass of block (in kg) (Take g = 10 m/s² )

In a container, 1 g of hydrogen and 1 g of oxygen are taken. Find the ratio of hydrogen pressure to oxygen pressure,

Find the temperature of H₂ gas at which its rms speed is equal to that of O₂ at 47°C.

In an isobaric process, the absolute temperature is doubled. The mean free path (l) and the  relaxation time (t) will become respectively