Once again a friend has a diff-e-q problem that he needs help with:

A woman bails out of an airplane at an altitude of 10,000 ft, falls freely for 20 s, then opens her parachute. How long will it take her to reach the ground? Assume linear air resistance v ft/s2, taking $\displaystyle \rho = 0.15$ without the parachute and $\displaystyle \rho = 1.5$ with the parachute.