A body of 2 kg has an initial speed 5 ${\mathrm{ms}}^{-1}$. A force acts on it for some time in the direction of motion. The force time graph is shown in figure. The final speed of the body is

Impulse = Change in momentum = $\mathrm{m}({\mathrm{v}}_2-{\mathrm{v}}_1)----\left(\mathrm{i}\right)$

Again impulse = Area between the graph and time axis

= $\frac{1}{2}\times 2\times 4+2\times 4+\frac{1}{2}(4+2.5)\times 0.5+2\times 2.5$

= 4+8+1.625+5 = 18.625----------(ii)

From (i) and (ii), m(${\mathrm{v}}_2-{\mathrm{v}}_1$) = 18.625

$\Rightarrow {\mathrm{v}}_2 = \frac{18.625}{\mathrm{m}}+{\mathrm{v}}_1 = \frac{18.625}{2}+5 = 14.3 \mathrm{m}/\mathrm{s}$