Fundamental Concepts of Physics

• Physics is a natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force
• It is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves

Core Concepts

• Mechanics: Deals with the motion of bodies under the action of forces
  • Includes kinematics (description of motion) and dynamics (causes of motion)
• Thermodynamics: Studies heat and its relation to other forms of energy
  • Deals with the laws governing energy transfer and entropy
• Electromagnetism: Concerned with the interactions between electric currents, magnetic fields, and electric charges
  • Includes electrostatics, electrodynamics, and magnetism
• Optics: Studies the behavior and properties of light
  • Includes reflection, refraction, diffraction, and interference
• Quantum Mechanics: Deals with the behavior of matter and energy at the atomic and subatomic levels
  • Introduces concepts such as quantization, wave-particle duality, and uncertainty

Fundamental Quantities and Units

• Length: Measured in meters (m)
• Mass: Measured in kilograms (kg)
• Time: Measured in seconds (s)
• Electric Current: Measured in amperes (A)
• Temperature: Measured in kelvin (K)
• Amount of Substance: Measured in moles (mol)
• Luminous Intensity: Measured in candelas (cd)

Key Laws and Principles

• Newton's Laws of Motion:
  • 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 a force
  • Second Law: Force equals mass times acceleration (F = ma)
  • Third Law: For every action, there is an equal and opposite reaction
• Law of Universal Gravitation: Describes the gravitational force between two masses
  • The force is proportional to the product of their masses and inversely proportional to the square of the distance between them
• Laws of Thermodynamics:
  • First Law: Energy is conserved
  • Second Law: Entropy of an isolated system tends to increase
  • Third Law: Entropy of a system approaches a constant value as temperature approaches absolute zero
• Maxwell's Equations: A set of four equations that describe the behavior of electric and magnetic fields
  • Gauss's law for electricity, Gauss's law for magnetism, Faraday's law of induction, and Ampère-Maxwell's law
• Schrödinger Equation: Describes the time evolution of quantum mechanical systems

Mechanics

• Kinematics:
  • Displacement: Change in position; a vector quantity
  • Velocity: Rate of change of displacement; a vector quantity
  • Acceleration: Rate of change of velocity; a vector quantity
• Dynamics:
  • Force: An interaction that, when unopposed, will change the motion of an object
  • Work: Energy transferred to or from an object by means of a force acting on the object
  • Energy: The capacity to do work. Includes kinetic energy (energy of motion) and potential energy (energy of position)
  • Power: Rate at which work is done or energy is transferred
  • Momentum: Product of mass and velocity; a vector quantity
  • Impulse: Change in momentum of an object

Thermodynamics

• Temperature: A measure of the average kinetic energy of the particles in a system
• Heat: Energy transferred between objects due to a temperature difference
• Entropy: A measure of the disorder of a system
• Heat Transfer:
  • Conduction: Transfer of heat through a material by direct contact
  • Convection: Transfer of heat by the movement of fluids
  • Radiation: Transfer of heat by electromagnetic waves
• Thermodynamic Processes:
  • Isothermal: Constant temperature
  • Adiabatic: No heat transfer
  • Isobaric: Constant pressure
  • Isochoric: Constant volume

Electromagnetism

• Electric Charge: A fundamental property of matter that causes it to experience a force when placed in an electromagnetic field; measured in coulombs (C)
• Electric Field: A region around an electric charge where other charges experience a force
• Electric Potential: Electric potential energy per unit charge; measured in volts (V)
• Capacitance: Ability of a body to store an electrical charge; measured in farads (F)
• Electric Current: Rate of flow of electric charge; measured in amperes (A)
• Resistance: Opposition to the flow of electric current; measured in ohms (Ω)
• Magnetic Field: A field produced by moving electric charges
• Magnetic Flux: Measure of the quantity of magnetism, taking account of the strength and the extent of a magnetic field
• Inductance: Property of an electrical conductor by which a change in current through it induces a voltage in both the conductor itself and in any nearby conductors; measured in henries (H)
• Electromagnetic Waves: Waves produced by the acceleration of electric charges; examples include light, radio waves, and X-rays

Optics

• Reflection: Bouncing back of light from a surface
• Refraction: Bending of light as it passes from one medium to another
• Diffraction: Spreading of waves as they pass through an opening or around an obstacle
• Interference: Superposition of waves, resulting in constructive (increase in amplitude) or destructive (decrease in amplitude) effects
• Lenses: Devices that refract light to form images
• Optical Instruments: Devices that use lenses and mirrors to enhance vision; examples include telescopes, microscopes, and cameras

Quantum Mechanics

• Wave-Particle Duality: The concept that every elementary particle or quantum entity exhibits the properties of not only particles, but also waves
• Quantization: The concept that energy, momentum, and other physical quantities are restricted to discrete values
• Uncertainty Principle: The principle that there is a fundamental limit to the precision with which certain pairs of physical properties of a particle, such as position and momentum, can be known simultaneously
• Quantum Entanglement: A phenomenon in which two or more particles become linked together in such a way that the state of one particle instantly influences the state of the other, regardless of the distance separating them
• Quantum Superposition: The principle that a quantum mechanical system can exist in multiple states simultaneously until measured

Physics is a natural science that studies matter, energy, and their interactions. The main goal of physics is to understand how the universe behaves through various core concepts. Key areas include mechanics, thermodynamics, electromagnetism, optics and quantum mechanics.