Question

In the figure given above, the position time graph of a particle of mass $0.1kg$ is shown. The impulse at $t=2sec$ is:

• A. $0.2kgmse{c}^{-1}$
• B. $-0.2kgmse{c}^{-1}$
• C. $0.1kgmse{c}^{-1}$
• D. $-0.4kgmse{c}^{-1}$

Answer 1

The correct option is B $-0.2kgmse{c}^{-1}$

Just before $2s$, velocity is given by slope of curve $=4/2=2m/s$
Just after, since $x-t$ graph is horizontal, hence $v=0$
Thus change in velocity, $\Delta v=0-2=-2m/s$
Thus impulse $=m\Delta v=0.1\times (-2)=-0.2kgm/s$