Apicture shows the letter "o" made from a piece of plastic. where is the center of gravity? use the definition of the center of gravity to explain how you could prove to someone why you put your dot where you did.

The center of gravity is at the center of the O(assuming it's a perfect circle) because a perfect circle has a constant radius, so the object is equidistant to the center. This means that the force of gravity on all aspects are equal. Say if you picked a point on the ring. There will always be another point opposite to that point where the gravity of that point counteracts against the gravity o the ring that you picked.