Answer
$a=-24\frac{m}{s^2}$
Work Step by Step
We have to find acceleration when $v=0$ (not including when $t=0$). From part(e), we have $t=4s$
Acceleration is given as:
$a=24-12t$
We plug in the value $t=4$ to obtain:
$a=24-12(4)$
$a=-24\frac{m}{s^2}$
