Question

The force F acting on a particle of mass is indicated by force-time graph shown below.The change in momentum of the particle over the time interval from zero to 8 s is

Answer 1

$\overrightarrow{F}=\frac{d\overrightarrow{p}}{dt}$ (Newton's second law )

$d\overrightarrow{p}=\overrightarrow{F}dt\overrightarrow{p}=\int \overrightarrow{F}dt$

Change in monmentum $\int \overrightarrow{F}dt$

=area under the curve of F-t graph

From the figure:

Change in momentum $=(\frac{1}{2}\times 2\times 6)+(-3\times 2)+(3\times 4)=6-6+12=12kgm/s$