An Object Moves Along a Line in Such a Way $s ( t ) = t ^ { 3 } - 39 t ^ { 2 } + 459 t + 2$

Multiple Choice

An object moves along a line in such a way that its position at time t is $s ( t ) = t ^ { 3 } - 39 t ^ { 2 } + 459 t + 2$ . Find the velocity and acceleration of the object at time t. When is the object stationary?

A) $v ( t ) = 3 t ^ { 2 } - 78 t + 459$ ; a(t) = 6t - 78; t = 9 and 17
B) $v ( t ) = 3 t ^ { 2 } - 78 t + 459$ ; a(t) = 6t - 78; t = 13
C) $v ( t ) = 3 t ^ { 2 } - 26 t + 459$ ; a(t) = 6t - 26; t = 9
D) $v ( t ) = 3 t ^ { 2 } - 78 t + 459$ ; a(t) = 6t - 78; t = 9