Branches of Physics

Branches of Physics

• Mechanics: Study of motion, force, energy, and gravity
• Thermodynamics: Study of heat, temperature, and energy transfer
• Electromagnetism: Study of electricity, magnetism, and electromagnetic waves
• Optics: Study of light, its properties, and behavior
• Quantum Mechanics: Study of atomic and subatomic particles
• Relativity: Study of space, time, and gravity

Fundamental Concepts

• Matter: Anything that has mass and occupies space
• Energy: Ability to do work, measured in joules (J)
• Space: Three-dimensional expanse that includes all matter and radiation
• Time: Measure of duration, measured in seconds (s)
• Mass: Amount of matter in an object, measured in kilograms (kg)

Key Laws and Principles

• Newton's Laws of Motion:
  1. Inertia: Objects at rest stay at rest, objects in motion stay in motion
  2. Force and Acceleration: Force = mass x acceleration (F = ma)
  3. Action and Reaction: Every action has an equal and opposite reaction
• Law of Universal Gravitation: Every point mass attracts every other point mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them
• Conservation of Energy: Energy cannot be created or destroyed, only converted from one form to another
• Conservation of Momentum: Momentum remains constant in a closed system

Important Constants and Units

• Speed of Light (c): 299,792,458 m/s
• Gravitational Constant (G): 6.67408e-11 N*m^2/kg^2
• Elementary Charge (e): 1.60217662e-19 C
• Avogadro's Number (NA): 6.022140857e23 particles
• Boltzmann Constant (kB): 1.38064852e-23 J/K

Branches of Physics

• Mechanics deals with motion, force, energy, and gravity
• Thermodynamics focuses on heat, temperature, and energy transfer
• Electromagnetism involves electricity, magnetism, and electromagnetic waves
• Optics is the study of light, its properties, and behavior
• Quantum Mechanics explores atomic and subatomic particles
• Relativity examines space, time, and gravity

Fundamental Concepts

• Matter is anything with mass that occupies space
• Energy is the ability to do work, measured in joules (J)
• Space is the three-dimensional expanse that includes all matter and radiation
• Time is a measure of duration, measured in seconds (s)
• Mass is the amount of matter in an object, measured in kilograms (kg)

Key Laws and Principles

Newton's Laws of Motion

• Inertia: Objects at rest stay at rest, objects in motion stay in motion
• Force and Acceleration: Force equals mass times acceleration (F = ma)
• Action and Reaction: Every action has an equal and opposite reaction

Other Key Laws and Principles

• Law of Universal Gravitation: Every point mass attracts every other point mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them
• Conservation of Energy: Energy cannot be created or destroyed, only converted from one form to another
• Conservation of Momentum: Momentum remains constant in a closed system

Important Constants and Units

• Speed of Light (c) is 299,792,458 m/s
• Gravitational Constant (G) is 6.67408e-11 N*m^2/kg^2
• Elementary Charge (e) is 1.60217662e-19 C
• Avogadro's Number (NA) is 6.022140857e23 particles
• Boltzmann Constant (kB) is 1.38064852e-23 J/K

Relativity

Special Relativity

• Albert Einstein introduced Special Relativity in 1905, challenging traditional notions of space and time
• Two key postulates:
  • Physical laws are identical for all observers in uniform motion
  • Speed of light remains constant regardless of observer or light source motion

Key Concepts

• Time dilation: moving observer experiences time slower than stationary observer
• Length contraction: moving observer sees objects as shorter than stationary observer
• Relativistic mass: object mass increases as velocity approaches light speed
• Mass-energy equivalence: mass (m) and energy (E) are interchangeable, E = mc^2

General Relativity

• Albert Einstein introduced General Relativity in 1915, incorporating gravity into Special Relativity
• Gravity is not a force, but curvature of spacetime caused by massive objects

Key Concepts

• Gravitational time dilation: time passes slower near massive objects due to stronger gravity
• Geodesic equation: shortest path through curved spacetime, governing motion under gravity
• Equivalence principle: gravity effects equivalent to acceleration effects

Implications and Applications

• GPS technology relies on relativistic corrections for accurate location and time
• Particle accelerators exploit relativistic mass increase for high-energy collisions
• Cosmological implications: understanding universe expansion and evolution