Water flows in a streamline motion through a horizontal pipe of circular cross-section as shown in the figure. The pressure difference of water…

Water flows in a streamline motion through a horizontal pipe of circular cross-section as shown in the figure. The pressure difference of water between $\displaystyle P$ and $\displaystyle Q$ is $\displaystyle 15 \mathrm{Nm}^{-2}$. The area of cross-section at $\displaystyle P$ and $\displaystyle Q$ are $\displaystyle 40 \mathrm{~cm}^2$ and $\displaystyle 20 \mathrm{~cm}^2$, respectively. The rate of flow of water through the pipe, in $\displaystyle \mathrm{cm}^3 \mathrm{~s}^{-1}$, is : [Take density of water $\displaystyle =1000 \mathrm{~kg} \mathrm{~m}^{-3}$ ]