Physics - Kinematics Question with Solution | TestHub

Area of a-t graph gives change in velocity at $\mathrm{t}=4\sec$

Area $=\frac{1}{2}\times 4\times 4=8\Rightarrow {\mathrm{v}}_{\mathrm{F}}-3=8\Rightarrow {\mathrm{v}}_{\mathrm{F}}=11\mathrm{m}/\mathrm{s}$

at $\mathrm{t}=8\sec$

Area $=8-1\times 4=4\Rightarrow {\mathrm{v}}_{\mathrm{F}}-3=4\Rightarrow {\mathrm{v}}_{\mathrm{F}}=7\mathrm{m}/\mathrm{s}$