Static balance refers to the ability of a stationary object to balance. It happens when the object’s center of gravity is on the axis of rotation. Dynamic balance, on the other hand, is the ability of an object to balance while in motion or switching between positions. In humans, both types of balance are necessary to ensure an active lifestyle.
For any form of balance to happen, the center of gravity must be aligned over the object’s support base. Center of gravity refers to the center of the object’s bodyweight. Balancing also plays an important role in machines. For instance the balancing of a rotating body helps to avoid vibration that can cause failure, especially in heavy industrial machines such as electric generators and gas turbines. Machine vibrations can also cause excessive noise and discomfort.
In some cases, balancing simply involves shifting the center of gravity toward the center of rotation. Dynamic balance is when the rotation in a rotating system does not yield any resultant centrifugal force or couple. Other than the force or couple needed for support, the system rotates without application of any external force. Maintaining a system in complete balance requires the closing of both forces and couple polygons.