Fundamental Concepts of Physics

Definition: Physics is the study of matter, energy, and the fundamental forces of nature.
Branches:
- Classical Mechanics
- Thermodynamics
- Electromagnetism
- Quantum Mechanics
- Relativity

Newton's Laws of Motion:
- First Law (Inertia): An object in motion stays in motion unless acted upon by an external force.
- Second Law (F=ma): The force acting on an object is equal to the mass of the object times its acceleration.
- Third Law (Action-Reaction): 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 in a closed system remains constant.
Thermodynamics:
- Zeroth Law: If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other.
- First Law: Energy is conserved in thermodynamic processes (ΔU = Q - W).
- Second Law: Entropy of an isolated system always increases.
- Third Law: As temperature approaches absolute zero, the entropy of a perfect crystal approaches a constant minimum.
Electromagnetism:
- Coulomb's Law: The force between two charged objects is proportional to the product of their charges and inversely proportional to the square of the distance between them.
- Faraday's Law of Induction: A changing magnetic field can induce an electric current.
Waves and Optics:
- Wave Properties: Wavelength, frequency, amplitude, and speed.
- Refraction: Bending of waves when passing from one medium to another.
- Reflection: Bouncing back of waves when they hit a barrier.

Kinematic Equations (for constant acceleration):
- v = u + at
- s = ut + 0.5at²
- v² = u² + 2as
Energy Equations:
- Kinetic Energy (KE): KE = 0.5mv²
- Potential Energy (PE): PE = mgh
- Total Mechanical Energy: E_total = KE + PE

SI Units:
- Length: meter (m)
- Mass: kilogram (kg)
- Time: second (s)
- Force: Newton (N)
- Energy: Joule (J)
Dimensional Analysis: Method to convert units and verify the consistency of equations.

Engineering: Principles of mechanics and thermodynamics in design.
Medicine: Medical imaging technologies like MRI and X-rays.
Environmental Science: Understanding energy transfer, climate models, and renewable energy sources.

Physics explores matter, energy, and the fundamental forces shaping the universe.
Major branches include Classical Mechanics, Thermodynamics, Electromagnetism, Quantum Mechanics, and Relativity.

Newton's Laws of Motion:
- First Law: Objects remain in their state of motion unless influenced by an external force.
- Second Law: The relationship between force (F), mass (m), and acceleration (a) is defined as F = ma.
- Third Law: Every action has an equal and opposite reaction.
Conservation Laws:
- Conservation of Energy: Energy transformations occur, but total energy remains unchanged.
- Conservation of Momentum: Momentum in a closed system is conserved over time.
Thermodynamics:
- Zeroth Law: Thermal equilibrium between two systems is established through a third system.
- First Law: Energy conservation in thermal processes expressed as ΔU = Q - W; internal energy change equals heat added minus work done.
- Second Law: Entropy tends to increase in isolated systems.
- Third Law: Entropy of a perfect crystal approaches zero as temperature approaches absolute zero.
Electromagnetism:
- Coulomb's Law: Force between charged objects is directly proportional to the product of charges and inversely proportional to the square of the distance.
- Faraday's Law of Induction: A time-varying magnetic field can generate an electric current.
Waves and Optics:
- Key properties of waves include wavelength, frequency, amplitude, and speed.
- Refraction occurs when waves change direction passing through different media.
- Reflection is the bouncing back of waves upon striking an obstacle.

Kinematic Equations for motion with constant acceleration include:
- v = u + at
- s = ut + 0.5at²
- v² = u² + 2as
Energy Equations:
- Kinetic Energy (KE) calculated as KE = 0.5mv².
- Potential Energy (PE) given by PE = mgh.
- Total Mechanical Energy is the sum of KE and PE: E_total = KE + PE.

SI Units:
- Length measured in meters (m).
- Mass measured in kilograms (kg).
- Time measured in seconds (s).
- Force measured in Newtons (N).
- Energy measured in Joules (J).
Dimensional Analysis: A technique utilized for unit conversion and equation consistency verification.

Engineering: Utilizes mechanics and thermodynamics for innovative designs and solutions.
Medicine: Advances in medical imaging techniques including MRI and X-rays are rooted in physics principles.
Environmental Science: Physics aids in understanding energy transfer, influencing climate models and supporting renewable energy development.

Isaac Newton: Known for formulating the laws of motion and law of universal gravitation.
Albert Einstein: Revolutionized physics with the introduction of the theory of relativity.
Niels Bohr: Contributed to quantum theory and the understanding of atomic structure.
James Clerk Maxwell: Formulated foundational principles in electromagnetism, unifying light and electromagnetic waves.