The Package Drop

In this movie, you see a simulation of a package being dropped by an airplane that is flying with a constant velocity in the horizontal and no velocity in the vertical.  This situation is very similar to an object sent horizontally off a cliff.  There are several key pieces of information that are always true in this situation if we are ignoring the effects of air friction.

• The falling object always begins with an initial velocity of zero in the vertical (Y) direction.
  So
• The horizontal velocity () of the object is always the same as it was the instant it started to fall.  (the same as the airplane's velocity)
• Since air friction is being ignored, there is nothing to change the horizontal velocity of the falling object.  So which means that the horizontal velocity () would be constant. Notice how the horizontal spacing is the same between each image of the package.  You should also notice that the package is always right beneath the airplane.
• The vertical acceleration is the acceleration due to gravity ().  Which causes the package's velocity to increase as it falls.  Notice the increasing vertical spacing between each image of the package.
• The horizontal displacement traveled by the package () after being dropped is dependant only upon the height of the airplane () and the velocity of the airplane upon dropping the package ().

©1998 Science Joy Wagon