The equations for free fall at the surfaces of Venus and Jupiter ($s$ in meters, $t$ in seconds) are $s = 4.435 t^2$ on Venus and $s = 12.975 t^2$ on Jupiter.

(a) How long does it take a rock falling from rest to reach a velocity of $27.8 \ \mathrm{m/s}$ (about $100 \ \mathrm{km/hr}$) on each planet?
On Venus: seconds
On Jupiter: seconds

(b) Using derivatives, what is the acceleration due to gravity on each planet?
On Venus: $\mathrm{m/s^2}$
On Jupiter: $\mathrm{m/s^2}$