The words that are said to be the centre and gravity are derived from the Latin or we can say in Greek words that are “centrum” and “gravitation”. The centre of the centroid that is said to represent the mass that is of the centre in the cross-section of the diagonals of the body. The gravity is the weight of the forces which are attractive which is between particles in the universe under which the celestial bodies move.
The centre of the mass that we have seen is the point where the gravitational force is acting on the body.
If a particle or system of the body moves under the influence of an external force that is said to be the point at which the centre of gravity is to be located and it moves as if it contains all the mass of the system or body. If the body which we have taken is not with uniform density then we can say tha the centre of mass that is the gravity does not have to be in the geometric at the centre of the body. The position which is said to be of the centre of gravity for the particle system in the Cartesian coordinate system is determined by the vector or the radius vector rS = Σmiri / Σmi. Whereas the mi are the masses of the particles and then ri are the radius vectors of the particles. The position that is of the centre of the mass of the rigid body which is in the Cartesian coordinate system is to be determined by the radius vector that is rS = (∫rρdV) / M which is where letter r is the unit vector the symbol ρ is the body’s density and symbol V volume and M is the mass of the body.
One more thing we need to notice is that the geometric centre is referred to as centroid. Simply if we stay stated then we can say that the centroid corresponds with the centre of gravity which is in case when the body is homogeneous that is with constant density. We can say that if the body is said to be homogeneous then this point is said to be located in the intersection of the gravitational lines and along with that in right geometric bodies it is determined geometrically. The principle of Archimedes was the first to describe the process by which an object' that is we can say that the centroid can be found. He proposed the cutting process of a cardboard with the objects’ shape and piercing several holes in it. Then he told me to nail it on the wall on one of the holes and let it hang freely. Then we need to hang plumb on the same nail. Then we need to draw with a pencil the direction which is determined by the direction of the end of the plumb. This direction is generally known as the centre of gravity which is of the object. Hang the body on the other holes as well and then repeat the procedure.
The centre of gravity or we can say that the centre of mass is said to be the point where the whole mass of the body is concentrated. This is said to be where the gravitational force that is the weight of the body generally acts for any orientation of the body. The centroid which is said to be the centre which is of gravity for objects of uniform density.
The process of calculating the centre of gravity which is not a simple procedure because of the mass and then the weight that generally may not be uniformly distributed throughout the object. The centre of gravity which generally can be calculated from cg * that is represented as W = S x dw where x is the distance which is from a reference line that is said to be dw is an increment of weight and the letter that is W is the total weight of the object. Centroid can be found with methods such as the plumb line method which is discussed above in the article.
1. Explain what is the difference between Centre of gravity and Centre of mass?
The centre of mass which we have learnt already is the point at which the distribution of mass is said to be equal in all directions. and we can also say that it does not depend on the gravitational field. The Centre of gravity which we have learnt is the point at which the distribution of weight is said to be equal in all direction and does depend on the gravitational field.
2. Explain is the center of gravity always located in the centroid?
For simple and the rigid objects which are with uniform density so we can say that the center of mass is located at the centroid. For example we can say that the center of mass which is of a uniform disc shape would be at its center. Sometimes we can say that the center of mass doesn't fall anywhere on the object.
3. Explain what is center gravity?
We can here say that the centre of gravity. The term that is the centre of gravity in the science of physics. Suppose that there is an imaginary point in a body of matter where we can say for convenience in certain calculations that the total weight of the body may be thought to be concentrated.
4. Explain why the Centre of pressure is always below the centroid?
The center of pressure which is in general centroid since pressure increases with the increase in depth. We can say that the center of pressure is determined by equating the moments which i sof the resultant and distributed forces about any arbitrary axis.