If all of the forces acting on an object all add up to zero, then we say that <span>the group </span>of forces is balanced. When that happens, the group of forces has the same effect on the object as if there were no forces on it at all.
An example: Two people with exactly equal strength are having a tug-of-war. They pull with equal force in opposite directions. Each person is sweating and straining, grunting and groaning, and exerting tremendous force. But their forces add up to zero, and the rope goes nowhere. The <u>group</u> of forces on the rope is balanced.
On the other hand, if one of the offensive linemen is pulling on one end of the rope, and one of the cheerleaders is pulling on the other end, then their forces don't add up to zero, because even though they're opposite, they're not equal. The <u>group</u> of forces is <u>unbalanced</u>, and the rope moves.
A group of forces is either balanced or unbalanced. A single force isn't.
