given equation = mass of toy car = 2 kg
at t = 10 s.
Formula needed to solve the question.
F orce = mass × acceleration
velocity = acceleration × time

$\mathrm{F}=\mathrm{ma};\mathrm{a}=\frac{\mathrm{v}}{\mathrm{t}}\Rightarrow \mathrm{F}=\mathrm{m}\times \frac{\mathrm{v}}{\mathrm{t}}$

⇒ F × t = m × v

impulse (area under the graph gives impulse)

$\Rightarrow \text{ velocity }=\frac{\text{ impulse }}{\text{ mass }}\Rightarrow \frac{\text{ area moles the graph }}{\text{ mass }}$

area under the graph upto 10(s)

$\Rightarrow \left(\frac{1}{2}\times 8\times 4\right)-\left(\frac{1}{2}\times 1\times 2\right)-(1\times 2)$

⇒ 16 – 1 – 2 = 13

$\text{ velocity }=\frac{\text{ area under the graph }}{\text{ mass }}=\frac{13}{2}=6.5 \mathrm{m}/\mathrm{s}$