Question

A plane flying horizontally at 384 m/s releases a package at an altitude of 15,721 m.

Answer 1

Answer:

t = 56.6 s

Explanation:

In the absence of air resistance we can use the kinematic equation

s = ½at²

The package is at vertical rest at the drop point. The horizontal velocity will not matter.

t = √(2s/a)

t = √(2(15721)/9.81)

t = 56.6 s

With air resistance, the time will likely be significantly longer as terminal velocity probably has  been achieved.

Without air resistance, the velocity at ground impact would be

v = at = 9.81(56.6) = 555 m/s

which is almost double the speed of sound in air, so air resistance is not negligible.