Projectile Thrown Horizontally / Driven Off a Cliff
In this movie, you see a simulation of a projectile being shot horizontally off a cliff which is identical to an object being driven off a cliff. This situation is also very similar to an object being dropped from a horizontally flying airplane. There are several key pieces of information that are always true in this situation if we are ignoring the effects of air friction.
- The projectile 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. (However fast it was shot or being driven when it left
the edge of the cliff.) - 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 projectile. - The vertical acceleration is the acceleration due to gravity (
). Which causes the
projectile's velocity to increase as it falls. Notice the increasing vertical
spacing between each image of the package. - The horizontal displacement traveled by the projectile (
) after being shot is dependent
only upon the height of the cliff (
) and the horizontal velocity of the projectile or car as it left the edge of
the cliff ().
