Question

The velocity of a body varies with time as $V=3t^2+2$. Find the instantaneous acceleration $t=3sec$

• A. $31m/s^2$
• B. $18m/s^2$
• C. $3m/s^2$
• D. $-2/3m/s^2$

Answer 1

The correct option is B $18m/s^2$

$\angle PQR=\angle LMN$ (PQ$\parallel$LM)

$v=3t^2+2$

$\Rightarrow$ acceleration $a=\frac{dv}{dt}=6t$

$\therefore$ Instantaneous acceleration at $t=3sec=6\times 3=18m/s^2$

(B)