Classic case: Coyote chases road-runner in a foggy area. Road runner stops with a smug look on its face. Coyote pauses, then reaches below his feet to find nothing but air. As the fog starts to fade, the coyote looks down to see the ground several hundred feet below him. At this point, gravity takes over. In succession, then, the coyote's feet fall, then his body, then his head.
Whether shot from a cannon or in hot pursuit on foot, cartoon characters are so absolute in their momentum that only a telephone pole or an outsize boulder retards their forward motion absolutely. Sir Isaac Newton called this sudden termination of motion the stooge's surcease.
Also called the silhouette of passage, this phenomenon is the speciality of victims of directed-pressure explosions and of reckless cowards who are so eager to escape that they exit directly through the wall of a house, leaving a cookie-cutout-perfect hole. The threat of skunks or matrimony often catalyzes this reaction.
Such an object is inevitably priceless, the attempt to capture it inevitably unsuccessful.
Psychic forces are sufficient in most bodies for a shock to propel them directly away from the earth's surface. A spooky noise or an adversary's signature sound will induce motion upward, usually to the cradle of a chandelier, a treetop, or the crest of a flagpole. The feet of a character who is running or the wheels of a speeding auto need never touch the ground, especially when in flight.
This is particularly true of tooth-and-claw fights, in which a character's head may be glimpsed emerging from the cloud of altercation at several places simultaneously. This effect is common as well among bodies that are spinning or being throttled. A `wacky' character has the option of self- replication only at manic high speeds and may ricochet off walls to achieve the velocity required.
This trompe l'oeil inconsistency has baffled generations, but at least it is known that whoever paints an entrance on a wall's surface to trick an opponent will be unable to pursue him into this theoretical space. The painter is flattened against the wall when he attempts to follow into the painting.
This is ultimately a problem of art, not of science.
Cartoon cats possess even more deaths than the traditional nine lives might comfortably afford. They can be decimated, spliced, splayed, accordion-pleated, spindled, or disassembled, but they cannot be destroyed. After a few moments of blinking self pity, they reinflate, elongate, snap back, or solidify.
See Itchy and Scratchy cartoons for a particularly good example of this law.
Corollary: A cat will assume the shape of its container.
This quirk in the law of gravity can be seen in an endless series of experiments involving anvils and boulders. A coyote, after securing an anvil with an industrial-sized rubber band to two cacti, will launch the anvil in such a trajectory that it will loosen any number of odd-sized boulders from their resting places, causing them to roll or fall from any given cliff directly onto the coyote-- in the order in which the pain of impact gradually increases. The anvil will always return to the coyote.
This is the one law of animated cartoon motion that also applies to the physical world at large. For that reason, we need the relief of watching it happen to a duck instead.