The position of a particle moving along a line is given by

MATHEMATICS · Single correct · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

s(t)=t^{3}-6t^{2}+9t+2

, where

t

is measured in seconds and

s

in meters. On the interval

0\le t\le 4

, at which time(s) does the particle change direction? (a)

t=2

only (b)

t=1

only (c)

t=1 \text{ and } t=3

(d) The particle never changes direction on

[0,4]