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Falling Analyzed (Part 2)

Page history last edited by Alejandro Garcia 12 years, 6 months ago

Now let's look at some more advanced examples of falling motion.

Rolling Off a Table

The combination of sideways (horizontal) motion and falling is actually quite simple since slowing out only occurs in the vertical direction. This is most easily seen by tracking the motion of a ball rolling off of a table.

Parabolic Arcs

The motion of a thrown ball is similar to that of a ball rolling off a table; in both cases the sideways motion is uniform while slowing in and out occurs in the vertical spacings.

Tipping & Falling

A brick falling off of a table is a more complicated type of motion. Nevertheless, once the brick is in the air the falling motion is similar to a ball rolling off of a table. Notice that while the brick slows out as it falls vertically, the brick's rotation rate stays constant as it falls.

The timing and spacing of the initial tipping of the brick are more complex than in the slowing out of a falling ball. This is because the acceleration is not constant so the rotation is initially very slow but increases dramatically just before the brick loses contact with the table. Also note how the brick's rotation causes it to move away from the table; the path of action in the air is a parabolic arc.

Squash without Bounce

When a rigid objects, like a baseball, falls and hits the ground there is a very small squash on impact. A more interesting squash occurs when a soft object, such as a sack of flour, hits the ground. Although the sack does not bounce off the ground after impact, there is a noticable "puff up" after impact.

Squash with Bounce

Fluid objects, like a water balloon, have a very interesting, complex squash on impact, which is revealed when you see it in slow motion. Notice that during the settle the vibration frequency of the "jiggling" stays nearly constant while the amplitude of those vibrations slowly dies out.

Animation Tutorial

For more information on how to animate motion on a path of action, download the Physics of Paths of Action tutorial.