Description: Demonstrations with a heavy rod show that holding it farther from its center of mass increases the torque required to maintain balance.
Key Terms: Lever arm, center of mass, pivot point, force, gravity

For a given body, the center of mass is the average position of all the mass that makes up the object. For example, a symmetrical object, such as a ball, has its center of mass at its geometrical center; by contrast, an irregularly shaped body, such as a baseball bat, has more of its mass toward one end. The center of mass of a baseball bat, therefore, is toward the thicker end. A solid cone has its center of mass exactly one-fourth of the way up from its base.