Physics

Problem

A particle moves along a straight line such that its velocity varies with time as follows: • at

t = 0\,\text{s}

v = 30\,\text{m/s}

; • it decreases uniformly to

v = 0

t = 3\,\text{s}

; • without any change in magnitude of acceleration, it continues to

v = -20\,\text{m/s}

t = 5\,\text{s}

; • it then moves with this constant velocity up to

t = 9\,\text{s}

. Taking the starting point as the origin and positive velocity as the positive direction, the displacement of the particle at

t = 9\,\text{s}

is a)

-35\,\text{m}

+55\,\text{m}

-55\,\text{m}

-25\,\text{m}