If the distance `s` metre traversed by a particle in `t` seconds is given by `s=t^(3)-3t^(2)`, then the velocity of the particle when the acceleration is zero, in metre/second is

Options

A. 3
B. -2
C. -3
D. 2

Answer

C

Explanation

Given `s=t^(3)-3t^(2)`
`implies(ds)/(dt)=3t^(2)-6t`…………..i
`implies(d^(2)s)/(dt^(2))=6t-6=0`………..ii
`t=1`
On putting values of `t=1` in eq. (i) we get
`(ds)/(dt)=3xx1-6xx1=-3m//s`