Classical Mechanics and Electromagnetism

Classical Mechanics

• Classical mechanics describes the motion of macroscopic objects, including planets, cars, and balls.
• It is based on Newton's laws of motion and gravitation.
• Newton's first law: An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
• Newton's second law: The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. (F = ma)
• Newton's third law: For every action, there is an equal and opposite reaction.
• Key concepts include: force, mass, acceleration, momentum, energy, work, and power.
• Applications include: calculating trajectories of projectiles, analyzing the motion of planets, and designing machines.

Electromagnetism

• Electromagnetism describes the interaction between electric and magnetic fields.
• Electric charges produce electric fields, and moving charges produce both electric and magnetic fields.
• Electric force is described by Coulomb's law.
• Magnetic force is dependent on both the strength and direction of the magnetic field and the velocity of the moving charge.
• Faraday's law of induction describes how changing magnetic fields create electric fields.
• Key concepts include: electric charge, electric field, electric potential, magnetic field, magnetic flux, electromagnetic induction, and electromagnetic waves.
• Applications include: generating electricity, designing motors, and transmitting information wirelessly.

Thermodynamics

• Thermodynamics deals with heat, temperature, and energy transfer.
• Key concepts are: internal energy, heat, work, temperature, entropy, and the laws of thermodynamics.
• The First Law of Thermodynamics: Energy cannot be created or destroyed; only transformed from one form to another.
• The Second Law of Thermodynamics: The total entropy of an isolated system can only increase over time.
• The Third Law of Thermodynamics: The entropy of a system approaches a constant value as the temperature approaches absolute zero.
• Applications include: designing engines, refrigerators, and other thermal devices.

Optics

• Optics deals with the behavior of light.
• Light travels in waves or as photons, depending on the context.
• Key concepts include: reflection, refraction, diffraction, interference, polarization, and lenses.
• Reflection: Change in direction of a light ray when striking a surface.
• Refraction: Bending of light as it passes from one medium to another.
• Diffraction: Spreading of light as it passes through an aperture or around an obstacle.
• Interference: Superposition of two or more waves to create a resultant wave.
• Applications include: designing telescopes, microscopes, and eyeglasses.

Modern Physics

• Modern physics encompasses theories that describe the physical world at the atomic and subatomic level, or at very high speeds.
• Key concepts include: special relativity, general relativity, quantum mechanics, and nuclear physics.
• Special relativity: Describes the relationship between space and time for inertial observers.
• General relativity: Explains gravity as a curvature of spacetime caused by mass and energy.
• Quantum mechanics: Describes the behavior of matter and energy at the atomic and subatomic level. It involves discrete energy levels and probabilistic descriptions.
• Nuclear physics: Deals with the structure and behavior of atomic nuclei.
• Applications include: understanding the universe, designing nuclear power plants, and developing new technologies.