Solve the given problems by finding the appropriate derivative.
A package of weather instruments is propelled into the air to an altitude of about 7 km. A parachute then opens, and the package returns to the surface. The altitude of the package as a function of the time t (in min) is given by
![2285_809cdabb-c07b-4e75-8b16-d6f6ab95471c.png](https://secure.tutorsglobe.com/CMSImages/2285_809cdabb-c07b-4e75-8b16-d6f6ab95471c.png)
Find the vertical velocity of the package for t = 8.0 min.