An overview of the fundamental concepts and principles of physics, including the scientific method, units of measurement, and the role of physics in understanding the natural world.
Introduction to Physics – Study Notes
| Concept | Meaning | Typical Example |
|---|---|---|
| System | The part of the universe chosen for analysis (e.g., a falling ball, an electric circuit). | A block sliding down an incline. |
| Reference Frame | A coordinate system and set of observers used to describe motion. | Earth‑bound frame vs. a spacecraft frame. |
| Quantity | Measurable property (scalar or vector). | Mass (scalar), velocity (vector). |
| Unit | Standardized measurement for a quantity (SI system is most common). | Kilogram (kg), meter (m), second (s). |
| Law | A concise mathematical relationship derived from repeated experiment. | Newton’s second law: F = ma. |
| Theory | A coherent set of principles that explains a broad range of phenomena and makes testable predictions. | Quantum mechanics, general relativity. |
| Branch | Primary Focus | Representative Topics |
|---|---|---|
| Classical Mechanics | Motion of macroscopic objects under forces. | Kinematics, dynamics, conservation laws. |
| Thermodynamics & Statistical Mechanics | Energy, heat, and the collective behavior of many particles. | Laws of thermodynamics, entropy, kinetic theory. |
| Electromagnetism | Electric and magnetic fields and their interactions. | Maxwell’s equations, circuits, optics. |
| Optics | Behavior of light. | Reflection, refraction, diffraction, lasers. |
| Quantum Physics | Behavior of matter and energy at atomic and sub‑atomic scales. | Wave‑particle duality, Schrödinger equation, quantum states. |
| Relativity | Motion at high speeds and gravitation as spacetime curvature. | Special relativity (time dilation), general relativity (black holes). |
| Condensed Matter | Properties of solids and liquids. | Crystallography, superconductivity, semiconductors. |
| Particle Physics | Fundamental particles and forces. | Standard Model, Higgs boson, collider experiments. |
| Astrophysics & Cosmology | Physics of celestial objects and the universe as a whole. | Stellar evolution, cosmic microwave background, dark matter. |
| Quantity | Symbol | SI Unit | Description |
|---|---|---|---|
| Length | L | meter (m) | Distance between two points. |
| Mass | m | kilogram (kg) | Measure of inertia. |
| Time | t | second (s) | Duration of events. |
| Electric Current | I | ampere (A) | Flow of charge. |
| Temperature | T | kelvin (K) | Measure of thermal energy. |
| Amount of Substance | n | mole (mol) | Number of entities (atoms, molecules). |
| Luminous Intensity | Iv | candela (cd) | Perceived power of light. |
Derived quantities (e.g., velocity v, acceleration a,