Mechanical Motion

Mechanical motion is the change in the position of a body relative to another body over time. Mechanics, a branch of physics, studies mechanical motion
and forms the foundation of all physics.

Classical mechanics (or Newtonian mechanics) describes the motion of bodies at speeds that are not comparable to the speed of light.

The main task of mechanics is to determine the position of a body at a given moment in time or at a given point in its trajectory.

Types of Mechanical Motion

Mechanical motion is the change in the relative position of bodies over time. The position of a body in space is determined only in relation to other bodies.

By Shape and Trajectory:

• Rectilinear: Motion along a straight line.
• Curvilinear: Motion along a curved path.

By the Nature of the Movement of Individual Points of the Body Relative to Each Other:

• Translational: Motion in which all points of the body move identically.
• Rotational: Motion in which the body rotates around a fixed axis.

By the Nature of the Change in Speed:

• Uniform: Motion with constant speed.
• Non-uniform: Motion with variable speed.

Translational Motion

Translational motion is the movement in which all points of the body move identically. The property of translational motion is that the trajectories of all points
are congruent (parallel).

Rotational Motion

Rotational motion is the movement in which a body rotates around a fixed axis. An example of rotational motion is the rotation of the Earth around its axis.

Oscillatory Motion

Oscillatory motion is the movement in which a body periodically returns to its initial position. An example of oscillatory motion is the movement of a clock
pendulum.

Abstract Concepts in Mechanics

1. Material Point: A body whose dimensions can be neglected under the given conditions of the problem, provided that:

   • The dimensions of the body are much smaller than the distance it travels.
   • The dimensions of the body are much smaller relative to other bodies.
2. Reference Body: The body relative to which the position of the given body is considered.
3. Reference Point: A point in the coordinate plane relative to which the positions of bodies are marked.
4. x-coordinate: A number that shows the distance of the body from the origin (reference point).
5. x₀ – Initial Coordinate: The coordinate of the body at the initial moment of time.

Additional Concepts

• 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.
• 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).