A bullet is fired horizontally down an open cylinder of cross-sectional area ${10}^{-2}{\mathrm{m}}^2$ . When the gun is fired, bullet is at rest and the volume between the end of cylinder and bullet is $5\times {10}^{-4}{\mathrm{m}}^3$, and pressure of gas in this volume is 8P₀ where P₀ is atmospheric pressure. Gaseous mixture in the cylinder has $\gamma =1.5$. The bullet moves down quickly, so that no heat is transferred to the gas. Friction between bullet and the barrel is negligible and no gas leaks around bullet. $\left(P_0={10}^5\mathrm{N}/{\mathrm{m}}^2\right)$