The acceleration #39;a #39; in m/s^2 of

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The acceleration $'a'$ in $m/{s^2}$ of a particle is given by $a = 3{t^2} + 2t + 2$ where $t$ is the time. If the particle starts out with a velocity $u = 2\,m/s$ at $t = 0$, then the velocity at the end of $2$ second is.......$m/s$

A

$12$

B

$18$

C

$27$

D

$36$
The acceleration $'a'$ in $m/{s^2}$ of a particle is given by $a = 3{t^2} + 2t + 2$ where $t$ is the time. If the particle starts out with a velocity $u = 2\,m/s$ at $t = 0$, then the velocity at the end of $2$ second is.......$m/s$
$ v = u + \int_{}^{} {adt = u + \int_{}^{} {(3{t^2} + 2t + 2)dt} } $
$ = u + \frac{{3{t^3}}}{3} + \frac{{2{t^2}}}{2} + 2t = u + {t^3} + {t^2} + 2t$
$ = 2 + 8 + 4 + 4 = 18\;m/s$     (As $t = 2\, sec$)