This question consists of three small questions, using the same picture, but with different values.

$1$: The tank shown in the figure below had a circular cross$-$section of diamter D $=0\mathrm{.}5$ m$.$ It is being filled with water from sections $1$ and $2$ and drained from section $3.$ The flow is incompressible.

At a particular instant in time, the volumetric flow rates from sections $1,2$ and $3$ are Q$1=0\mathrm{.}046$ m$3/$s$,$ Q$2=0\mathrm{.}024$ m$3/$s and Q$3=0\mathrm{.}02$ m$3/$s respectively and the height in the tank is $0\mathrm{.}2$ m$.$

Calculate the rate of water$-$level change $($dh$/$dt$)$ in cm$/$s$.$

$2$: The tank shown in the figure below had a circular cross$-$section of diamter D $=0\mathrm{.}44$ m$.$ It is being filled with water from sections $1$ and $2$ and drained from section $3.$ The flow is incompressible.

At a particular instant in time, dh$/$dt $=0\mathrm{.}044$ m$/$s$,$ h $=0\mathrm{.}4$ m$,$ Q$1=0\mathrm{.}028$ m$3/$s and Q$3=0\mathrm{.}086$ m$3/$s$.$

Calculate the volumetric flow rate from section $2$ in m$3/$s$.$

$3$: The tank shown in the figure below had a circular cross$-$section of diamter D $=$ D m$.$ It is being filled with water from sections $1$ and $2$ and drained from section $3.$ The flow is incompressible.

The height in the tank, h $=0\mathrm{.}22$ m and is constant and Q$1=0\mathrm{.}048$ m$3/$s$,$ the area at section $2$ is A$2=90$ cm$2,$ the average velocity at sections $2$ is V$2=0\mathrm{.}82$ m$/$s$,$ and the area at section $3$ is A$3=80$ cm$2.$

Calculate the average velocity at sections $3,$ V$3$ in m$/$s$.$