Find both the general solution of the differential equation and the solution with the given initial condition.
$$
\mathbf{r}^{\prime \prime}(t)=16 \mathbf{k}, \quad \mathbf{r}(0)=\langle 1,0,0\rangle, \quad \mathbf{r}^{\prime}(0)=\langle 0,1,0\rangle
$$