# Delivering a Package by Air

1. Aug 31, 2006

### markiii

A relief airplane is delivering a food package to a group of people stranded on a very small island. The island is too small for the plane to land on, and the only way to deliver the package is by dropping it. The airplane flies horizontally with constant speed of 200 mph at an altitude of 850 m . The positive x and y directions are defined in the figure. For all parts, assume that the "island" refers to the point at a distance D from the point at which the package is released, as shown in the figure. Ignore the height of this point above sea level. Assume that the acceleration due to gravity is g = 9.80 .m/s^2
After a package is ejected from the plane, how long will it take for it to reach sea level from the time it is ejected? Assume that the package, like the plane, has an initial velocity of 200 in the horizontal direction.
If the package is to land right on the island, at what horizontal distance D from the plane to the island should the package be released?
What is the speed v_f of the package when it hits the ground

2. Aug 31, 2006

### markiii

i need help bad i'm so confused

3. Aug 31, 2006

### lightgrav

do the vertical motion first, because the altitude sets the time of fall.

you DO know how far it falls, right?
do you know how to write that vertical location as a function of time?
You realize that the vertical speed starts out as zero?