Fundamental Concepts in Physics

Definition: Physics is the study of matter, energy, and the fundamental forces of nature.
Branches:
- Classical Mechanics: Motion and forces.
- Electromagnetism: Electric and magnetic fields and their interactions.
- Thermodynamics: Heat, energy transfer, and laws governing energy exchange.
- Quantum Mechanics: Behavior of particles at atomic and subatomic levels.
- Relativity: Effects of gravity and high speeds on time and space (Einstein's theories).

Newton's Laws of Motion:
- First Law: An object in motion stays in motion unless acted upon by an external force.
- Second Law: Force equals mass times acceleration (F = ma).
- Third Law: For every action, there is an equal and opposite reaction.
Conservation Laws:
- Conservation of Energy: Energy cannot be created or destroyed, only transformed.
- Conservation of Momentum: The total momentum of a closed system remains constant.
Thermodynamics Laws:
- Zeroth Law: If two systems are in thermal equilibrium with a third, they are in equilibrium with each other.
- First Law: Energy conservation; change in internal energy equals heat added minus work done by the system.
- Second Law: Heat cannot spontaneously flow from a colder body to a hotter body.
Electromagnetic Theory:
- Coulomb’s Law: Electric forces between charges are proportional to the product of the charges and inversely proportional to the square of the distance between them.
- Faraday's Law of Induction: Changing magnetic fields induce an electromotive force (EMF).

Basic Units (SI system):
- Mass (kg)
- Length (m)
- Time (s)
- Electric Current (A)
- Temperature (K)
- Amount of Substance (mol)
- Luminous Intensity (cd)
Common Derived Units:
- Force (Newton, N = kg·m/s²)
- Energy (Joule, J = kg·m²/s²)
- Power (Watt, W = J/s)

Four Fundamental Forces:
- Gravitational: Attractive force between masses.
- Electromagnetic: Force between charged particles.
- Weak Nuclear: Responsible for radioactive decay.
- Strong Nuclear: Holds the nucleus together.

Motion Types:
- Linear: Movement in a straight line.
- Rotational: Movement around an axis.
- Projectile: Motion of an object thrown into the air subject to gravity.
Basic Equations of Motion (for constant acceleration):
1. (v = u + at)
2. (s = ut + \frac{1}{2}at^2)
3. (v^2 = u^2 + 2as)

Wave Properties:
- Amplitude: Maximum displacement from equilibrium.
- Wavelength: Distance between successive crests/troughs.
- Frequency: Number of oscillations per second (Hz).
Sound Waves:
- Longitudinal waves requiring a medium.
- Speed of sound varies with medium (faster in solids than gases).

Nature of Light:
- Electromagnetic wave exhibiting both wave and particle characteristics (wave-particle duality).
Optical Principles:
- Reflection: Bouncing back of light.
- Refraction: Bending of light when it passes through different media.
- Lenses: Converging and diverging lenses for image formation.

Quantum Theory: Describes particles and interactions at atomic and subatomic scales.
Relativity: Explains how time and space are intertwined and affected by speed and gravity.

Technology: Development in computing, telecommunications, and medical imaging.
Engineering: Principles applied in designing structures, vehicles, and systems.
Environmental Science: Understanding energy transfer, climate models, and renewable energy sources.

Physics explores matter, energy, and the fundamental forces of nature.
Major branches of physics include classical mechanics, electromagnetism, thermodynamics, quantum mechanics, and relativity.

Newton's Laws of Motion define the relationship between force, mass, and motion:
- First law: An object at rest stays at rest, and an object in motion stays in motion at a constant 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.
Conservation Laws state that certain quantities remain constant in closed systems:
- Conservation of Energy: Energy cannot be created or destroyed, only transformed from one form to another.
- Conservation of Momentum: The total momentum of a closed system remains constant.
Laws of Thermodynamics govern heat, energy transfer, and entropy:
- Zeroth Law: Two systems in thermal equilibrium with a third system are also in thermal equilibrium with each other.
- First Law: The change in a system's internal energy equals the heat added to the system minus the work done by the system.
- Second Law: Heat cannot spontaneously flow from a colder body to a hotter body.
Electromagnetic Theory describes electric and magnetic phenomena:
- Coulomb's Law: The force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
- Faraday's Law of Induction: A changing magnetic field induces an electromotive force (EMF).

The International System of Units (SI) defines seven base units, including:
- Mass (kilogram, kg)
- Length (meter, m)
- Time (second, s)
- Temperature (Kelvin, K)
Derived units are combinations of base units, including:
- Force (Newton, N = kg·m/s²)
- Energy (Joule, J = kg·m²/s²)
- Power (Watt, W = J/s)

The four fundamental forces explain all known interactions in the universe:
- Gravitational force: Attractive force between masses.
- Electromagnetic force: Force between charged particles, responsible for electricity and magnetism.
- Weak Nuclear force: Responsible for radioactive decay.
- Strong Nuclear force: Holds the nucleus of an atom together.

Types of Motion:
- Linear: Movement in a straight line.
- Rotational: Movement around an axis.
- Projectile: Motion of an object thrown into the air subject to gravity.
Equations of Motion for Constant Acceleration:
- (v = u + at) (final velocity, initial velocity, acceleration, time)
- (s = ut + \frac{1}{2}at^2) (displacement, initial velocity, acceleration, time)
- (v^2 = u^2 + 2as) (final velocity, initial velocity, acceleration, displacement)

Wave Properties:
- Amplitude: Maximum displacement from equilibrium.
- Wavelength: Distance between two successive crests or troughs.
- Frequency: Number of oscillations per second (Hz).
Sound Waves:
- Longitudinal waves that require a medium for propagation.
- The speed of sound varies with the medium, being faster in solids than gases.

Nature of Light:
- Electromagnetic wave exhibiting both wave and particle characteristics (wave-particle duality).
Optical Principles:
- Reflection: Bouncing back of light from a surface.
- Refraction: Bending of light as it passes from one medium to another.
- Lenses: Converging lenses focus light, while diverging lenses spread it out.

Quantum Theory: Describes the behaviors at and below the atomic level.
Relativity: Explains how time, space, and gravity are intertwined, especially at high speeds and strong gravitational fields.

Technology: Physics principles are used in developing computing, communication, medicine, and other technologies.
Engineering: Physics principles are applied in design, construction, and manufacturing.
Environmental Science: Physics helps us understand the flow of energy and develop renewable energy sources.