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 $0.01\text{ m}$ is given by the following equation: $$u(y) = 7.5 - 3 \times 10^5 y^2$$ where $y$ is the vertical distance measured from the center of the slit. The average velocity of the fluid (in $\text{m s}^{-1}$) is ____________ (rounded off to the nearest integer).