Answer
a) $\frac{dV}{dt}$=144$cm^{2}$/s
b) $\frac{dV}{dt}$=720$cm^{2}$/s
Work Step by Step
The surface area of a cube is A=6$a^{2}$
It is given that $\frac{da}{dt}$=6 cm/s
a)
a= 2 cm
A=6$a^{2}$
$\frac{dA}{dt}$=12a($\frac{da}{dt}$)
=12(2)(6)
=144 $cm^{2}$/s
b)
a=10 cm
A=6$a^{2}$
$\frac{dA}{dt}$=12a($\frac{da}{dt}$)
=12(10)(6)
=720 $cm^{2}$/s