Center of gravity vs center of mass

[atavistic]

Is it different from the center of mass? My book says yes but doesn't answer the question.

 

[arildno]

No, they are not the same.
You may look at the following post, a comment I made to one of the tutorials here at PF:
https://www.physicsforums.com/showpost.php?p=920266&postcount=2

 

[charng]

The center of gravity and center of mass are often used interchangeably, but they are actually slightly different concepts. The center of gravity is the point at which the weight of an object or system can be considered to act. It is the point where the gravitational force can be considered to be concentrated. On the other hand, the center of mass is the point at which the mass of an object or system is evenly distributed, regardless of the presence or absence of gravity.

In most cases, the center of gravity and center of mass will coincide, especially for objects on Earth where the force of gravity is relatively constant. However, in situations where there are varying gravitational forces, such as in space or on a non-uniform planet, the center of gravity and center of mass may differ.

It is important to note that while the center of gravity and center of mass are related, they are not the same. The center of mass is a property of an object, while the center of gravity is a point where external forces can be considered to act. Understanding the difference between these two concepts is crucial in accurately describing the motion and stability of objects and systems.