There is n moles of the monoatomic gas in the container. Molar mass of the gas = m,Total mass of the gas in the container, M = mnChange in KE of the gas when the container is suddenly stopped, i.e.,
This change in kinetic energy (ΔK) result in a change in internal energy (ΔU) of the gasΔU=nCvΔT=n(23R)ΔTHere, ΔT is the change in temperature of the gasAs