Chapter 12.6, Problem 4QCE

The projectile motion model $\text{r}(t)=\left(-\frac{1}{2}g{t}^2+s_0\right)\text{j}+t{\text{v}}_0$ describes the motion of an object with constant acceleration $\text{a}=\text{\_\_\_\_\_\_}$ and velocity function $\text{v}(t)=\text{\_\_\_\_\_\_}\text{.}$ The initial position of the object is $\text{\_\_\_\_\_\_\_}$ and its initial velocity is $\text{\_\_\_\_\_\_}\text{.}$