Introduction to 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
• Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves
• Physics employs the scientific method to validate physical theories, which aim to summarize the laws of nature

Core Concepts

• Mechanics: Deals with the motion of bodies under the action of forces, including statics (bodies at rest) and dynamics (bodies in motion)
• Thermodynamics: Studies heat, work, and energy, and the relationships between them
• Electromagnetism: Examines the interactions between electric currents, magnetic fields, and electric charges
• Optics: Focuses on the behavior and properties of light, including reflection, refraction, diffraction, and interference
• Quantum Mechanics: Studies the behavior of matter and energy at the atomic and subatomic levels

Branches of Physics

• Classical Mechanics: Describes the motion of macroscopic objects accurately as long as quantum effects and relativistic effects can be neglected
• Electromagnetism: Deals with the forces that occur between electrically charged particles
• Thermodynamics: Branch of physics concerned with heat and temperature and their relation to energy and work
• Quantum Mechanics: Deals with the behavior of matter and energy on the atomic and subatomic scales

Classical Mechanics

• Kinematics: Describes motion without considering its causes, focusing on displacement, velocity, and acceleration
• Newton's Laws of Motion:
  • First Law (Law of Inertia): An object at rest stays at rest, and an object in motion stays in motion with the same velocity unless acted upon by a net force
  • 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)
  • Third Law: For every action, there is an equal and opposite reaction
• Work and Energy: Work is the transfer of energy, and energy exists in various forms, including kinetic and potential energy
• Conservation of Energy: The total energy of an isolated system remains constant
• Momentum: The product of an object's mass and velocity; conserved in a closed system
• Rotational Motion: Describes the motion of rotating bodies, involving angular displacement, angular velocity, and torque

Electromagnetism

• Electric Charge: A fundamental property of matter that can be positive or negative
• Electric Field: A region around an electric charge where a force would be exerted on other charges
• Coulomb's Law: Describes the force between electric charges (F = k * q1 * q2 / r^2)
• Electric Potential: The electric potential energy per unit charge
• Capacitance: The ability of a system to store electric charge
• Electric Current: The flow of electric charge
• Magnetic Field: A region around a magnet or electric current where a magnetic force is exerted
• Ampere's Law: Relates the magnetic field to the electric current producing it
• Faraday's Law: Describes how a changing magnetic field induces an electromotive force (EMF)
• Maxwell's Equations: A set of four equations that describe the behavior of electric and magnetic fields
• Electromagnetic Waves: Waves of energy that propagate through space, including light, radio waves, and X-rays

Thermodynamics

• Temperature: A measure of the average kinetic energy of the particles in a substance
• Heat: The transfer of energy between objects due to a temperature difference
• Zeroth Law of Thermodynamics: If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other
• First Law of Thermodynamics: The change in internal energy of a system is equal to the heat added to the system minus the work done by the system (ΔU = Q - W)
• Second Law of Thermodynamics: The total entropy of an isolated system can only increase over time
• Entropy: A measure of the disorder or randomness of a system
• Heat Engines: Devices that convert thermal energy into mechanical work
• Refrigerators: Devices that transfer heat from a cold reservoir to a hot reservoir by using work

Optics

• Reflection: The bouncing of light off a surface
• Refraction: The bending of light as it passes from one medium to another
• Lenses: Devices that refract light to form images
• Interference: The superposition of waves, which can result in constructive or destructive interference
• Diffraction: The spreading of waves as they pass through an opening or around an obstacle
• Polarization: The alignment of the electric field vectors in a light wave
• Optical Instruments: Devices that use lenses and mirrors to form images, such as telescopes and microscopes

Quantum Mechanics

• Wave-Particle Duality: The concept that all matter exhibits both wave-like and particle-like properties
• Heisenberg Uncertainty Principle: It is impossible to know both the position and momentum of a particle with perfect accuracy
• Schrödinger Equation: A mathematical equation that describes the time evolution of quantum mechanical systems
• Quantum Entanglement: A phenomenon where two or more particles become linked together in such a way that they share the same fate, no matter how far apart they are
• Quantum Superposition: A principle of quantum mechanics that states that any two (or more) quantum states can be added together ("superposed") and the result will be another valid quantum state
• Quantum Tunneling: A quantum mechanical phenomenon where a particle can pass through a potential barrier, even if it does not have enough energy to overcome the barrier classically

Units and Measurements

• SI Units: The internationally agreed-upon system of units, including meter (m) for length, kilogram (kg) for mass, second (s) for time, ampere (A) for electric current, kelvin (K) for temperature, mole (mol) for amount of substance, and candela (cd) for luminous intensity
• Dimensional Analysis: A technique used to check the consistency of equations and to derive relationships between physical quantities

Problem Solving in Physics

• Identify the knowns and unknowns
• Draw a diagram
• Choose relevant equations
• Solve the equations
• Check the answer

Mathematical Tools

• Algebra
• Trigonometry
• Calculus
• Vectors