Projects in Physics Balancing the Center of Gravity

Hi, I'm Sean Tvelia and we're here at Suffolk County Community College to talk about how to balance objects using the center of gravity. The center of gravity is simply a location within an object that marks the average location of all of the mass in the object. For example, this meter stick, 100 centimeters long, the average mass would be located at the 50 centimeter mark. In order to balance and object, what needs to happen is the center of gravity or the center of mass must be at the lowest position. So if I hold the ruler stick at the 50 centimeter mark it balances relatively simply. If I hold it on an end such that the center of mass is higher than the lowest point, we reach an unstable balancing which requires a little bit of work to keep it balanced. In order to balance any object, we just need to find the center of mass and ensure that the center of mass is at the lowest point. So moving from a meter stick to this where I have unequal masses, a heavy mass on one side and a much lighter mass on the other, the center of mass is now located closer towards the larger sphere and as a result, I must balance it closer to the larger sphere. As long as we have an object where the center of mass is located below a pivot point, we can easily balance it such like this bird where the center of mass is located below the beak of the bird and as a result, the bird easily balances by its beak. And that's how you balance objects using the center of gravity.