The velocity profile for a fully developed laminar flow of an incompressible Newtonian fluid, at steady state, through a horizontal infinitely wide and long slit of gap 0.01 m is given by the following equation.
u(y) = 7.5 − 3 × 10⁵y²
where y is the vertical distance measured from the center of the slit. The average velocity of the fluid (in m s⁻¹) is ____________ (rounded off to the nearest integer).