Physics

Problem

A particle moves along a straight line as follows: it accelerates uniformly from

0

12\,\text{m/s}

in the first

4\,\text{s}

, then decelerates uniformly to

-6\,\text{m/s}

in the next

3\,\text{s}

, and finally continues at this constant velocity of

-6\,\text{m/s}

for another

2\,\text{s}

. Taking the positive direction as the initial direction of motion, determine the total displacement of the particle in the

9\,\text{s}

. a)

18\,\text{m}

21\,\text{m}

3\,\text{m}

33\,\text{m}