Motion In A Plane

If the initial velocity in horizontal direction of a projectile is unit vector \(\hat{i}\) and the equation of trajectory is \(y=5 x(1-x)\). The \(y\) component vector of the initial velocity is ______________ \(\hat{j}\). (\(\mathrm{Take}\) \(\left.\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}\right)\)