projectile

The package follows a parabolic path and remains directly below the plane at all times. As the package falls, it undergoes a vertical acceleration; that is, there is a change in its vertical velocity. This vertical acceleration is attributed to the downward force of gravity which acts upon the package. If the package's motion could be approximated as projectile motion (that is, if the influence of air resistance could be assumed negligible), then there would be no horizontal acceleration. In the absence of horizontal forces, there would be a constant velocity in the horizontal direction. This explains why the package would be located directly under the plane from which it is dropped.