An open suction circuit wind tunnel operates with a $65$ kW motor whose efficiency is $80\%.$ The test section has a cross$-$sectional area of $3$ m$^2,$ the tunnel exit area is $8$ m$^2,$ and the air density is $1\mathrm{.}2$ kg$/$m$^3.$ Furthermore, the head loss along the tunnel is given by:

$2$ T $2$g h$=0\mathrm{.}05$

Where Vr is the speed in the test section. Calculate the speed in the wind tunnel test section