Q$3)$ A liquid flows downward through a tapered vertical pipe as shown in fig below. The pressure at section $1$ and $2$ are equal and the vertical distance between sections $1$ and $2$ is $H.$ the diameter at section $1$ is twice that at section $2.$ If $)=(1\mathrm{.}5m,$ determine the velocities at section $1$ and $2$ by assuming zero loss of energy between the two section.