A rigid body is not deformed by external forces.
A rigid body is one whose shape does not change despite being subjected to the action of external forces . This means that the distance between the different particles that make it up is invariant over time.
The rigid body is an ideal model used to carry out kinematics and mechanics studies . However, in practice, all bodies deform, even minimally, when subjected to the effect of an external force. Therefore, real machines and structures can never be considered absolutely rigid.
Kinematics and mechanics
We can establish that kinematics is a scientific branch, specifically framed within the field of physics, which has as its object of study what the movements of bodies are, without taking into consideration what the pressures or forces they are exposed to are. subjected.
It is also important to highlight the fact that the aforementioned scientific discipline develops its studies and analysis having three fundamental pillars for it. These are none other than time, space and mobile. All of this gives rise to subsequently working with what is uniformly accelerated rectilinear motion, simple harmonic motion, rectilinear motion, circular motion or parabolic motion, among others.
Meanwhile, the aforementioned mechanics also carries out the study of the movement of bodies but also their rest. Two questions in which he also studies what the forces that act on them are.
The study of pulleys is one of the fundamental fields of work within this aforementioned scientific branch that we find with the fact that it has several branches. In this way, there is relativistic quantum mechanics , relativistic mechanics, quantum mechanics and classical mechanics. The latter is divided into two: statistical mechanics and continuous means mechanics.
Specifically, the last of all those exposed is the one that focuses on studying in depth what acoustics, deformable solids and fluids are.
Rigid bodies are theoretical constructions: in practice, all bodies register some type of change when influenced by an external force.
Movements of a rigid body
There are different modes of motion of a rigid body. Translation consists of the transfer of the body, so that, at each instant, the particles that form it maintain the same speed and acceleration .
With rotation , particles move relative to an axis with the same velocity and angular acceleration .
When translation and rotation are combined, general motion appears, which is studied from the translation and rotation of the center of mass.
Specialists often study the effect of forces exerted on the rigid body to determine how a system of forces can be replaced by a simpler equivalent system. For this, they rely on the assumption that the effect of the force remains unchanged as long as the force moves in its line of action, which means that forces can be represented by sliding vectors .
Among the fundamental concepts for these studies are the moment of force with respect to its axis and the moment of force with respect to a point, which allow different calculations to be carried out.