$A$ tube of length $L$ is shown in the figure. The radius of the cross-section at point $(1)$ is $2 \ cm$ and at point $(2)$ is $1 \ cm$. If the velocity of water entering at point $(1)$ is $2 \ m/s$,then the velocity of water leaving at point $(2)$ will be: (in $m/s$)

Explain critical speed,white water rapids,and turbulent flow.

Select the correct statement regarding streamline flow.

Explain streamlines and streamline flow.

The surface of water in a water tank of cross-sectional area $750 \,cm^2$ on the top of a house is '$h$' $m$ above the tap level. The speed of water coming out through the tap of cross-sectional area $500 \,mm^2$ is $30 \,cm/s$. At that instant, $\frac{dh}{dt}$ is $x \times 10^{-3} \,m/s$. The value of '$x$' will be:

Water flows through a horizontal pipe at a speed $V$. The internal diameter of the pipe is $d$. If the water is emerging from a nozzle at a speed $V_{1}$,then the diameter of the nozzle is