Newton.
The center of gravity of a magnet is typically in the middle of the magnet, where the mass is evenly distributed. For a coin, the center of gravity is near the geometrical center as long as the mass is evenly distributed.
The center of gravity for a spherical object is located at the exact center of the sphere. This point is equidistant from all points on the surface of the sphere, making it the point where the force of gravity can be considered to act on the object.
Only if the object is homogeneous, i.e. the mass is uniformly distributed. If the object is lumpy, or has thick spots and thin spots, then the center of gravity isn't related to the geometric shape. Consider a see-saw with a light kid on one end and a heavy kid on the other end. The geometric center is the mid-point of the board, but the center of gravity is closer to the heavy kid.
The center of gravity of a circular bangle is at the geometrical center of the bangle, which is also the center of the circle. This point is equidistant from all points on the circumference of the bangle, making it the point where the weight of the bangle can be considered to act.
The center of mass is a geometrical measurement not considering the weight distribution. The center of gravity is one location on a particular mass structure where the distribution of weight is the same no matter the direction of the measurement as it pertains to that one particular mass structure.
Lodz is in the center of Poland, almost in the geometrical center of the country.
It is always different depending on the object. For example a female humans' center of gravity is in the hip. as a male humans' center of gravity is in the chest. But once you have found the center of gravity in an object the center of gravity should be the same in every object like it.
If the object is a thin lamina with uniform thickness (e.g. a piece of paper), the the centre of gravity of the object is at its geometrical centre. It can be determined by suspending a load (e.g. pendulum) on an edge of the lamina twice and the point where the plumb lines intersect is the centre of gravity.
The center of gravity of a triangle can be found by adjusting the thickness. You also need to find the density at the intersection.
Yes, the person would be weightless. The person would have to be at the center of gravity of the earth, which would probably be extremely near the geometrical center. Any difference between the two points would have to do with the homogeneous distribution of materials of similar mass. Since we know the earth has various bulges here and there, it is not impossible that the distribution of materials may be a little 'off', resulting in the center of gravity not being exactly at the geometric center.
The earth pulls every molecule of an object in a downwards direction, or in other words every molecule of an object has a weight. We can add all the millions of tiny molecule weights together and get a single resultant force for the weight of the whole object. So an object behaves as if its whole weight was a single force which acts through a point G called its centre of gravity. An object of uniform thickness and density has its mass evenly spread throughout and its centre of gravity is at its geometrical centre. Some examples of objects with regular shapes and uniform densities are shown in the figures below. It is interesting to note the centre of gravity of an object is not necessarily inside the object.
The center of gravity of the truck