3.1. Newton's first law

Lecture



Newton's first law says: every body maintains a state of rest or a uniform rectilinear motion, until exposure from other bodies causes it to change this state. The first law of Newton shows that the state of rest or uniform rectilinear motion does not require external influences for its maintenance: This manifests a special dynamic property of bodies, called inertness. Accordingly, the first Newton's law is usually called the law of inertia, and the motion of a body free from external influences is called motion by inertia.

3.1. Newtons first law

Experience shows that Newton's first law is not satisfied in any frame of reference. The reference systems in relation to which the law of inertia is fulfilled are called inertial reference systems. That is, these are such reference systems with respect to which the material point, on which other bodies do not act, either rests or moves uniformly and straightforwardly.

created: 2014-09-13
updated: 2026-03-08
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Lectures and tutorial on "Physical foundations of mechanics"

Terms: Physical foundations of mechanics

1. Subject mechanics. Kinematics. Introduction
1.1. The radius vector of the material point
1.2.Kinematic equations of motion of a material point
1.3. Material point trajectory
1.4.Vector movement
1.5. Material point velocity
1.6. Acceleration
1.7. Curved motion. Tangential and normal acceleration
1.8. Guidelines for solving problems in kinematics
2. Kinematics of rotational motion. Introduction
2.1. Angle of rotation of a solid body
2.3. Period and frequency of treatment
2.4. Angular acceleration
2.2. Angular velocity
2.5. The relationship of angular and linear quantities
3.1. Newton's first law
3.2. Concept of power
3.3. Weight. Newton's Second Law
3.4. The principle of independence of action of forces
3.5.Third Newton's Law
3.6 Transformation of Galilean coordinates and the mechanical principle of relativity
3.7.The basic equation of the dynamics of the translational motion of a material point. Material point impulse
3.8. Center of Inertia System
3.9. Universal form of the second law of Newton, expressed through the impulse of the system
3.10. The basic equation of the dynamics of the translational motion of a rigid body
3.11.Isolated (closed) system. Momentum conservation law
3.12. Guidelines for solving problems in dynamics
4.1. Basic concepts about the energy of a mechanical system
4.2. Mechanical work
4.3. Conservative forces. Condition of potentiality of the force field
4.4. Power
4.5 Kinetic energy
4.6.Potential energy
4.7. The law of conservation and transformation of energy
4.8. Relationship between potential energy and power
5. Dynamics of rotational motion of a rigid body. Introduction
5.1. Features of rotational motion
5.2. Torque (or moment of force)
5.3. The moment of inertia of the material point relative to a fixed axis of rotation
5.4. Moment of inertia of a solid
5.5. Newton's second law for rotational motion and its analysis
5.6. Moment of impulse of the material point and solid
5.7. The basic equation of the dynamics of rotational motion
5.8. The law of conservation of moment of momentum
5.9. Gyroscope. Gyroscopic effect
5.10. Kinetic energy of a rotating body
5.11. The work of external forces during the rotation of a solid body
6. Special theory of relativity. Introduction
6.1. Lorentz transformations
6.2. Simultaneity of events in different reference systems
6.3. The length of bodies in different systems
6.4. Duration of events in different reference systems
6.5. Relativistic law of velocity addition
6.6. Relativistic impulse