Introduction to Physics

• Physics is the 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.

Core Concepts

• Mechanics: Deals with the motion of bodies under the action of forces.
  • Kinematics describes motion without regard to its causes.
  • Dynamics studies the effect of forces on motion.
  • Statics deals with bodies at rest.
• Thermodynamics: Study of energy, heat, and work, and the laws governing these quantities.
  • Deals with the relationships between heat and other forms of energy.
  • Concepts include entropy, enthalpy, and the laws of thermodynamics.
• Electromagnetism: Study of the electromagnetic force, one of the four fundamental forces.
  • Includes electrostatics, electrodynamics, magnetism, and optics.
  • Governed by Maxwell's equations.
• Optics: Study of light and its behavior.
  • Includes reflection, refraction, diffraction, and interference.
  • Divided into geometrical optics and physical optics.
• Quantum Mechanics: Study of the very small.
  • Deals with the behavior of matter and energy at the atomic and subatomic levels.
  • Introduces concepts like wave-particle duality and quantization.
• Nuclear Physics: Study of the constituents, structure, behavior, and interactions of atomic nuclei.
  • Includes radioactivity, nuclear reactions, and nuclear energy.

Classical Mechanics

• 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.
• Energy: The capacity to do work.
  • Kinetic Energy: Energy of motion (KE = 1/2 mv^2).
  • Potential Energy: Stored energy due to position or condition.
• Conservation Laws:
  • Conservation of Energy: Energy cannot be created or destroyed, only transformed.
  • Conservation of Momentum: In a closed system, the total momentum remains constant.
  • Conservation of Angular Momentum: In a closed system, the total angular momentum remains constant.

Thermodynamics

• Zeroth Law: If two systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
• First Law: The change in internal energy of a system equals the heat added to the system minus the work done by the system (ΔU = Q - W).
• Second Law: The total entropy of an isolated system can only increase over time.
• Third Law: As temperature approaches absolute zero, the entropy of a system approaches a minimum or zero.

Electromagnetism

• Electric Charge: A fundamental property of matter that causes it to experience a force when placed in an electromagnetic field.
• Electric Field: A field of force surrounding an electric charge.
• Magnetic Field: A field of force created by moving electric charges.
• Maxwell's Equations: A set of four equations that describe the behavior of electric and magnetic fields.
  • Gauss's Law for Electricity: Relates electric field to electric charge.
  • Gauss's Law for Magnetism: States that there are no magnetic monopoles.
  • Faraday's Law of Induction: Describes how a changing magnetic field creates an electric field.
  • Ampere-Maxwell Law: Relates magnetic field to electric current and changing electric field.

Optics

• Reflection: The bouncing of light off a surface.
  • Law of Reflection: The angle of incidence equals the angle of reflection.
• Refraction: The bending of light as it passes from one medium to another.
  • Snell's Law: Relates the angles of incidence and refraction to the indices of refraction of the two media.
• Diffraction: The spreading of waves as they pass through an opening or around an obstacle.
• Interference: The combination of two or more waves to create a new wave pattern.

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 simultaneously know the exact position and momentum of a particle.
• Schrödinger Equation: A fundamental equation in quantum mechanics that describes how the quantum state of a physical system changes over time

Nuclear Physics

• Radioactivity: The spontaneous emission of particles or energy from an unstable nucleus.
  • Alpha Decay: Emission of an alpha particle (helium nucleus).
  • Beta Decay: Emission of a beta particle (electron or positron).
  • Gamma Decay: Emission of a gamma ray (high-energy photon).
• Nuclear Reactions: Processes in which nuclei interact, resulting in a change in their energy, composition, or structure.
• Nuclear Fission: The splitting of a heavy nucleus into two or more lighter nuclei, releasing energy.
• Nuclear Fusion: The combining of two or more light nuclei to form a heavier nucleus, releasing energy.