Sunday, March 1, 2009
What is center of gravity ?
The center of gravity of a collection of masses is the point where all the weight of the object can be considered to be concentrated. In physics, the center of gravity of an object is the average location of its weight in a particular environment (and relative to a particular reference point). In a (hypothetical) uniform gravitational field, it coincides with the object's center of gravity. For this reason (i.e. that in everyday experience the Earth's gravitational field may be considered uniform) the center of gravity (CG) of an object is a point at which the object's mass can be assumed, for many purposes, to be concentrated.
Center of mass
In physics, the center of mass of a system of particles is a specific point at which, for many purposes, the system's mass behaves as if it were concentrated. The center of mass is a function only of the positions and masses of the particles that comprise the system. In the case of a rigid body, the position of its center of mass is fixed in relation to the object (but not necessarily in contact with it). In the case of a loose distribution of masses in free space, such as shot from a shotgun, the position of the center of mass is a point in space among them that may not correspond to the position of any individual mass.
Difference between center of gravity and center of mass
Unlike the center of mass, the center of gravity of an object can vary, depending on the objects environment. Note that the center of gravity of a body is not a point such that the gravitational field due to that body is equal to the gravitational field if all mass were concentrated there. Such a point usually does not exist. For example for two equal spherical bodies the center of gravity of the system is forced by symmetry, and lies midway between the centers; but gravity due to the system is not very large near that point.
Videos ! :
Reference taken from : http://www.nationmaster.com/encyclopedia/Center-of-gravity and http://www.nationmaster.com/encyclopedia/Center-of-mass
The center of gravity of a collection of masses is the point where all the weight of the object can be considered to be concentrated. In physics, the center of gravity of an object is the average location of its weight in a particular environment (and relative to a particular reference point). In a (hypothetical) uniform gravitational field, it coincides with the object's center of gravity. For this reason (i.e. that in everyday experience the Earth's gravitational field may be considered uniform) the center of gravity (CG) of an object is a point at which the object's mass can be assumed, for many purposes, to be concentrated.
Center of mass
In physics, the center of mass of a system of particles is a specific point at which, for many purposes, the system's mass behaves as if it were concentrated. The center of mass is a function only of the positions and masses of the particles that comprise the system. In the case of a rigid body, the position of its center of mass is fixed in relation to the object (but not necessarily in contact with it). In the case of a loose distribution of masses in free space, such as shot from a shotgun, the position of the center of mass is a point in space among them that may not correspond to the position of any individual mass.
Difference between center of gravity and center of mass
Unlike the center of mass, the center of gravity of an object can vary, depending on the objects environment. Note that the center of gravity of a body is not a point such that the gravitational field due to that body is equal to the gravitational field if all mass were concentrated there. Such a point usually does not exist. For example for two equal spherical bodies the center of gravity of the system is forced by symmetry, and lies midway between the centers; but gravity due to the system is not very large near that point.
Videos ! :
Reference taken from : http://www.nationmaster.com/encyclopedia/Center-of-gravity and http://www.nationmaster.com/encyclopedia/Center-of-mass
what we could have been, 1:42 AM.
