Answer
The angle of $\vec{v}$ at that moment is
$$-79.4^{\circ} \text { or } 101^{\circ}
$$
Work Step by Step
The angle of $\vec{v}$ at that moment is
$$
\tan ^{-1}\left(\frac{-16.0 \mathrm{m} / \mathrm{s}}{3.00 \mathrm{m} / \mathrm{s}}\right)=-79.4^{\circ} \text { or } 101^{\circ}
$$
where we choose the first possibility $(79.4^{\circ} $ measured clockwise from the direction, or $281^{\circ} $ counterclockwise from $ x)$ since the signs of the components imply the vector is in the fourth quadrant.
