Mathematics

Problem

A particle’s velocity on the interval

-4\le t\le4

seconds is given by

v(t)=2-|t|

meters per second. At which of the following times does the particle change direction? a)

t=2\text{ s}

only b)

t=-2\text{ s}

and

t=2\text{ s}

t=-2\text{ s},\,0\text{ s},\,2\text{ s}

t=0\text{ s}

only