The velocity of a particle is given by

PHYSICS · Single correct · CBSE · Physics · Motion in a Plane · Motion in a Plane

Problem

\mathbf v(t)=\bigl(4t\,\text{i}-3t^{2}\,\text{j}+6\,\text{k}\bigr)\,\text{m s}^{-1}

. Find its instantaneous speed at

t=2\,\text{s}

. (a)

20.0\,\text{m s}^{-1}

(b)

15.6\,\text{m s}^{-1}

(c)

14.4\,\text{m s}^{-1}

(d)

18.8\,\text{m s}^{-1}