The position of an object at any time t is given by s ( t ) = 3 t 4 − 40 t 3 + 126 t 2 − 9 s ( t ) = 3 t 4 − 40 t 3 + 126 t 2 − 9 . Determine the velocity of the object at any time t. Does the object ever stop changing? When is the object moving to the right and when is the object moving to the left?