Center of Gravity

Every object has a center of gravity. It is the single point where all the weight of the object is perfectly balanced. If you could support an object at its center of gravity, it would balance perfectly. Understanding center of gravity helps explain why things tip over or stay standing.

Finding the Balance Point

You can find the center of gravity of a ruler by balancing it on one finger. The point where it balances is the center of gravity. For a symmetrical object like a ball, the center of gravity is right in the middle. For oddly shaped objects, the center of gravity might be closer to the heavier end.

Staying Balanced

An object stays standing as long as its center of gravity is over its base. If the center of gravity moves past the edge of the base, the object tips over. This is why a tall, narrow vase tips easily but a wide, short bowl does not. It is also why you lean forward when carrying a heavy backpack.

Fun Facts

• The Leaning Tower of Pisa does not fall because its center of gravity is still over its base.
• Tightrope walkers carry a long pole to lower their center of gravity and improve balance.
• A double-decker bus is tested to make sure it will not tip over on hills by checking its center of gravity.

Did You Know?

You can balance a fork and spoon on the edge of a glass using the center of gravity. If you stick a toothpick between them and find the right spot, the whole thing balances like magic!