From Mechanics

We use the expression for the position vector obtained in part a), \displaystyle \mathbf{r}=(8\mathbf{i}+10\mathbf{j})t+\frac{1}{2}(-10\mathbf{j}){{t}^{\ 2}}

From part a) the ball hits the ground when \displaystyle t=2\text{ s}.

The distance along the ground is the \displaystyle \mathbf{i} component giving \displaystyle 16\text{ m}