Difference between Centre of Mass and Centre of Gravity

Physics has always been an interesting subject. The topics such as gravity, inertia, distance, displacement, etc., are some of the interesting topics to work on. Science is a broad field that deals with certain systems like the human body, the solar system, plant tissue, animal tissue, chemicals, etc. But today, we will be discussing about two broad terms that are often used in physics, i.e., center of gravity and center of mass. Now, what do they mean? What are the significant differences between them? These questions might trouble the students. So, let us begin by discussing the basic meaning of these terms.

Centre of Mass

When the objects are weighed according to their masses, it is known as the center of mass. In astrophysics, it is defined as the distribution of mass in space. The weight of an object in space turns to zero irrespective of the mass they have. In order to calculate the center of mass, one needs to calculate the masses of the objects and then multiply them by their positions. Then one has to add them and divide them by the sum of masses. This is the formula of the center of mass. However, the formula changes depending upon the type of the object and its position. Well, it is interesting to note that the center of mass is required primarily in astrophysics and astronomy. In astronomy, the center of mass is defined as the place where two bodies balance and orbit around each other. For instance, the center of any object is the middle of the object, like the center of mass of the book, are the middle pages of the book.

Centre of Gravity

Gravity is found in every object. The center of gravity is the point at which the act of gravity takes place. In humans, the mass is concentrated. In layman's language, the center of gravity is defined as the point at which the object's weight acts in response to gravity. The center of gravity is necessary to determine the properties of an object. The center of gravity is directly proportionate to the stability of an object. For instance, if the center of gravity of a car is relatively low, the stability will be high. The center of gravity is calculated by summing up the weight of an object and dividing it by the origin of the object. Now, let us look at the difference between the center of gravity and the center of mass.

So, these are some of the differences between the center of gravity and the center of mass. Let us now look at some properties of both of them.

Characteristics of Centre of Mass

The center of mass is an essential part of astrophysics and astronomy because it focuses on how the bodies of balance and orbit around each other. The characteristics for the same are given below.

1. The center of mass depends upon the position of the object.
2. In the solar system, the mass of an object turns to zero.
3. The center of mass depends upon the distribution of mass along with the shape of an object.
4. The center of mass changes when the external force acted upon the object.
5. When the external force is not applied to an object, the center of mass possesses and moves at a constant velocity.
6. The objects with symmetrical dimensions, the center of gravity, and the center of mass correspond with one another.
7. The person possesses the same mass despite being in a different location.
8. The center of gravity might change, but the center of mass remains the same.
9. The center of mass weighs the mass of an object irrespective of its location and position.
10. There are three ways to measure the center of mass. They are:
    • Balance
    • Scale
    • SLAMMD (Space Linear Acceleration Mass Measurement Device)
    • Mass Sensor

Characteristics of Centre of Gravity

The center of gravity was first founded by Carl Von Clausewitz. He emphasized that the weight of an object acts in response to the gravitational force applied to it. The characteristics for the same are given below.

1. The gravity of an object can be determined by physical process.
2. An asymmetrical object has a center of gravity.
3. The center of gravity is useful for maintaining the stability of an object.
4. If an object has a uniform gravitational field, then the center of gravity and center of mass coincide with one another.
5. The size and shape of an object affect the center of gravity.
6. When an object is unable to balance itself, stability is affected.

So, these are some of the characteristics of the center of gravity and center of mass. Both center of mass and center of gravity is essential for maintaining and calculating the motion and stability of an object. The object is in motion when the center of mass is good. Similarly, the object's gravity ensures stability. Thus, both the center of gravity and the center of mass are important parts of physics.