Physics

Problem

An object moves in a straight line with an initial velocity of

8.0\,\text{m/s}

. It experiences a constant acceleration of

2.0\,\text{m/s}^2

for an unknown time

t

, after which the acceleration instantly changes to

-3.0\,\text{m/s}^2

for the next

10\,\text{s}

. At the end of the

10\,\text{s}

interval the object is momentarily at rest. Which of the following is the value of

t

? a)

9.3\,\text{s}

11\,\text{s}

6.0\,\text{s}

15\,\text{s}