Two vertical tanks placed on a platform are connected by a horizontal pipe having a $5$ cm inside diameter. Each tank is $2$ m deep and has a diameter of $1$ m$.$ At first, the valve on the pipe is closed and one tank is full while the other one is empty. When the valve is opened, the average velocity $($m$/$s$)$ through the pipe is given by v $=2*$sqrt$($h$)$ where h is the difference between the levels in the two tanks $($m$).$ Calculate the time for the levels in the two tanks took become equal. Use material balance and put all the values to be understandable and show explicitly how to get an answer of $4\mathrm{.}7$ m