Timing, or the speed of an action, is an important principle because it gives meaning to movement. The speed of an action defines how well the idea will be read to the audience.
Timing can also defines the weight of an object. Two similar objects can appear to be vastly different weights by manipulating timing alone.
For example, if you were to hit a croquet ball and a balloon with a mallet, the result would be two different actions. The croquet ball would require more force to place it into motion, would go farther, and need more force to stop it. On the other hand, the balloon would require far less force to send it flying, and because of it's low mass and weight, it wouldn't travel as far, and would require less force to stop it.
Timing can also contribute to size and scale of an object or character. A larger character has more mass, more weight and more inertia than a tiny character, therefore it moves slower. In contrast, a tiny character has less mass, weight, and inertia, therefore its movements are quicker.
Timing plays an essential role in illustrating the emotional state of an object or character. It is the varying speed of the characters movements that indicate whether a character is lethargic, excited, nervous, or relaxed.