An object is projected with a velocity of $20\,\text{m/s}$ making an angle of $45^\circ$ with horizontal. The equation for the trajectory is $h = Ax - Bx^2$ where $h$ is height, $x$ is horizontal distance, $A$ and $B$ are constants. The ratio $A : B$ is $(g = 10\,\text{m/s}^2)$