Crying can be dangerous

A girl named Anjali always cries for some or the other reason such as not getting her sheet back or taking her bag without permission One day I thought of having all the tears from her eyes collected in a long cylindrical tank of cross section area 0.5 $m^{2}$ . It has a small hole at a height 50 $cm$ from the bottom. A movable piston of cross-sectional area almost equal to 0.5 $m^{2}$ is fitted on the top of tank such that it can slide in the tank freely. A load of $20kg$ is applied on the top of the collected tears by piston. Calculate the speed in $m/sec$ of tear jet with which it hits the surface when piston is $1m$ above the bottom.( Ignore the mass of piston).

$Note:$ The tears collected are equivalent to water. $g$ = 9.8 $m/sec^{2}$

Suppose your ans. is z $m/sec$ Then find $[m]$ . Where $[.]$ denotes greatest integer function