A particle moves with a constant acceleration $\left(2 \mathrm{~m} / \mathrm{s}^{2}\right)$ Its initial velocity is $10 \mathrm{~m} / \mathrm{s}$. Find velocity after $\mathrm{t}$ second.
(A) $(10+\mathrm{t}) \mathrm{ms}^{-1}$
(B) $5(2+\mathrm{t}) \mathrm{ms}^{-1}$
(C) $2(5+\mathrm{t}) \mathrm{ms}^{-1}$
(D) $\left(10+\mathrm{t}^{2}\right) \mathrm{ms}^{-1}$