Question

Displacement-time equation of a particle moving along x-axis is

$x=20+t^3-12t$ (SI Units). Find position of particle when velocity of particle is zero.

Answer 1

Velocity of the particle $\frac{dx}{dt}=v=3t^2-12$ m/s

Let the time be $t$ when its velocity is zero.

$\therefore$ $0=3t^2-12$ $⟹t=2$ s

$\therefore$ Position of the particle at this instant $x{|}_{t=2s}=20+2^3-12\left(2\right)=4$ m