Section of Physics - Mechanics

Mechanics is the science of the mechanical movement of material bodies and the interactions between them that occur during this movement.

Mechanical movement refers to the change over time in the relative position of bodies or their particles in space. Examples of mechanical movement include
the motion of celestial bodies, the fall of objects under the influence of Earth's gravity, various types of oscillations, ocean currents, and the movement of air
masses, as well as various movements in technology. Mechanical movement can be observed in everyday life, such as the movement of cars, trains, airplanes,
and even the movement of people and animals.

Interactions are the actions of bodies on each other, resulting in changes in the velocities of points of these bodies or their deformations. Examples of
interactions include the attraction of bodies according to the law of universal gravitation, the pressure of touching bodies on each other, the impact of gas
or liquid particles on each other or on bodies moving within them. Interactions can be both contact (e.g., friction) and long-range (e.g., gravity).

Subdivisions of Mechanics:

1. Classical Mechanics: Based on Newton's laws of mechanics, which describe the motion of bodies with speeds much less than the speed of light.
   Classical mechanics includes sections such as kinematics, dynamics, and statics. Kinematics studies the motion of bodies without considering the
   causes of this motion. Dynamics examines the causes of motion and interactions of bodies, while statics studies the conditions of equilibrium of bodies.

2. Theory of Relativity: Examines the motion of bodies at speeds close to the speed of light. The theory of relativity was developed by Albert Einstein and
   includes both special and general relativity. Special relativity deals with the motion of bodies in inertial reference frames, while general relativity describes
   gravity as the curvature of spacetime.

3. Quantum Mechanics: Studies intra-atomic phenomena and the motion of elementary particles. Quantum mechanics describes the behavior of particles
   at the microscopic level, where classical mechanics ceases to be applicable. The main principles of quantum mechanics include Heisenberg's uncertainty
    principle and wave-particle duality.

Abstract Concepts in Mechanics:

1. Material Point: An object of negligible size that has mass (used in translational motion or in motion where the rotation of the body around its center of mass
   can be neglected). The material point is used to simplify problems when the size and shape of the body are not significant for describing its motion.

2. Absolutely Rigid Body: A body whose distance between any two points always remains unchanged (used when the deformation of the body can be
   neglected). The absolutely rigid body is used to describe the motion and interaction of bodies when their deformations are small and do not affect the
   results of calculations.

3. Continuous Medium: A medium whose molecular structure can be neglected. The continuous medium is used to describe the motion of liquids and gases
   when it can be assumed that they fill the entire space uniformly and continuously.

Basic Kinematic Measures of Motion:

• Velocity: A vector quantity that characterizes the rate of change of the position of a body in space. Velocity can be constant or variable. In the case
  of variable velocity, the concept of instantaneous velocity is introduced, which is defined as the derivative of the coordinate with respect to time.

• Acceleration: A vector quantity that characterizes the rate of change of the velocity of a body. Acceleration can be constant or variable. In the case
  of variable acceleration, the concept of instantaneous acceleration is introduced, which is defined as the derivative of velocity with respect to time.

Basic Measure of Mechanical Interaction of Material Bodies:

• Force: A vector quantity that characterizes the interaction between bodies, causing a change in their velocity or deformation. Force is the cause of the
  change in the motion of bodies and is defined by Newton's second law as the product of the mass of the body and its acceleration. Forces can be
  contact (e.g., friction force) and long-range (e.g., gravitational force).

Applications of Mechanics

Mechanics finds wide application in various fields of science and technology. It is used to calculate the trajectories of spacecraft, design machines and
mechanisms, analyze the movement of vehicles, study the behavior of liquids and gases, and in biomechanics to study the movement of living organisms.
Mechanics also plays an important role in construction, where it is used to calculate the strength and stability of buildings and structures.

History of the Development of Mechanics

Mechanics has a long history of development, starting from ancient times. The first ideas about the motion and interaction of bodies were formulated by ancient
Greek philosophers such as Aristotle. However, modern mechanics began to develop in the 17th century with the works of Galileo Galilei and Isaac Newton.
Newton formulated three laws of motion, which became the foundation of classical mechanics. In the 20th century, Albert Einstein developed the theory of relativity,
and Max Planck and Werner Heisenberg laid the foundations of quantum mechanics.