Find the velocity $\vec{v}(t)$ and the speed $\|\vec{v}(t)\|$ of a particle with position $$x = 2t^{3}-6t^{2},\quad y = 8,\quad z = 3t^{2}-12t+12.$$

$\vec v(t) =$
speed $\|\vec v(t)\| =$

Find any times at which the particle stops.

$t =$
(Give your answer as a time or list of times, comma separated.)