Introduction to Physics and its Branches

This set explores the fundamental definition of physics, distinguishes between classical and modern categories, and defines each major branch and its real-world applications.

Physics

The science that studies matter, energy, and how the two interact.

Classical Physics

A category of physics that focuses on macroscopic phenomena and everyday experiences involving motion, forces, and energy.

Modern Physics

A category of physics that explores microscopic phenomena at high speeds and strong gravitational fields, including behavior at the atomic level and the nature of space, time, and gravity.

Mechanics

The branch of physics that studies motion and the forces that cause it, explaining how objects move and interact.

Thermodynamics

The branch of physics that studies heat and energy flow, focusing on how energy is transferred and transformed in various systems.

Electromagnetism

The branch of physics that studies interactions in electric and magnetic fields, explaining electricity flow and magnetic behavior.

Optics

The study of light, its behavior, and its interaction with matter, applied in devices like eyeglasses and microscopes.

Acoustics

The branch of physics focused on how sound is produced and transmitted, often used in soundproofing and underwater exploration.

Relativity

The branch of physics that studies the interconnection of time, space, and motion, especially how they are affected by strong gravitational fields.

Particle physics

The study of fundamental particles, their interactions, and the forces acting on them to understand the deepest structures of atoms.

Convection

A heat transfer process where hot water rises as it becomes less dense and cooler water sinks, creating a circular current that distributes heat.

Newton’s laws & impulse–momentum

Principles used in helmet design to increase impact time and spread force, thereby reducing acceleration on the skull.

Electromagnetic radiation and absorption

The principle used in X-ray machines where radiation penetrates soft tissue but is absorbed by denser materials like bone.

Projectile motion

The physics of an object moving along a curved path under the influence of gravity after being launched.

Mechanical advantage and work–energy

Principles applied in simple machines (like levers or drills) to redistribute force, allowing the same work to be done with a smaller input force over a longer distance.

Joule heating

The process of energy conversion where electrical energy in circuits is partly converted to heat ($\text{current} \rightarrow \text{heat}$), occurring when devices run many programs.