All Problems

First law of thermodynamics, heat capacity

Problem 2.42

Find the rate \(v\) with which helium flows out of a thermally insulated vessel into vacuum through a small hole. The flow rate of the gas inside the vessel is assumed to be negligible under these conditions. The temperature of helium in the vessel is \(T=1,000 \mathrm{~K}\).

Reveal Answer
v=2γRT/(γ1)M=3.3 km/sv=\sqrt{2 \gamma R T /(\gamma-1) M}=3.3 \mathrm{~km} / \mathrm{s}