From Mechanics

We insert \displaystyle t=8\ \text{s} in the expression for the position vector,

\displaystyle \begin{align} & \mathbf{r}=\left( 5\times 8-{{8}^{2}} \right)\mathbf{i}+\left( 7\times 8 \right)\mathbf{j}+0\mathbf{k} \\ & \\ & =-24\mathbf{i}+56\mathbf{j}+0\mathbf{k}\ \text{m} \\ \end{align}