Question

The position (x)-time (t) graph for a particle of mass 1 kg moving along x-axis is
shown in figure. Find impulse on particle at t = 4 s.

Answer 1

$m=1kg$

Impulase at $4s\Rightarrow ?$

Velocity of particle:-

From $\underset{\left(Acceleration\right)}{0to4sec}\to \frac{20}{4}=5m/s$

From $\underset{\left(Deceleration\right)}{4secto8sec}\to \frac{-20}{4}=-5m/s$

Thus, Change in momentum :-

= Final - Initial

$=-\left(5m/s\right)\left(1kg\right)-\left(5m/s\right)\left(1kg\right)$

$=-5kgm/s-5kgm/s$

$=-10kgm/s$

$\therefore$ Impulse = change in momentum

$=-10kg/m/s$