Each edge of a cube grows at 3 cm/s. How fast is its volume growing when an edge is 4 cm long?

Explanation

1. 01

   $V = a^{3}$, so $\frac{dV}{dt} = 3a^{2} \frac{da}{dt}$.

2. 02

   $= 3 \times 16 \times 3 = 144$ cm³/s.