Introduction to Physics

• Physics is a natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force
• Physics is among the most fundamental scientific disciplines; the main goal is to understand how the universe behaves

Core Concepts

• Classical mechanics describes the motion of macroscopic objects like projectiles, machinery, spacecraft, planets, stars, and galaxies
• Thermodynamics addresses heat, work, energy, and their interrelationships
• Electromagnetism concerns the interactions of electric currents and magnetic fields
• Optics studies the behavior and attributes of light, including its interactions with matter and the design of optical instruments
• Quantum mechanics describes the behavior of matter and energy at atomic and subatomic scales
• Relativity, encompassing Special and General Relativity, explains spacetime structure and gravity, especially at high speeds and in strong gravitational fields
• Particle physics explores the basic components of matter and the forces governing their interactions

Key Principles

• Conservation Laws: Physics uses conservation laws (energy, momentum, angular momentum, electric charge) to understand physical phenomena
• Symmetry: Symmetries in physical systems often correspond to conservation laws and are valuable for physics
• Fields: Physical phenomena are described using fields like electromagnetic and gravitational fields, which mediate interactions between objects
• Quantum phenomena are probabilistic, described by wave functions
• Relativity includes spacetime, length contraction, time dilation, and the equivalence of mass and energy

Important Quantities and Units

• Length: meters (m)
• Mass: kilograms (kg)
• Time: seconds (s)
• Electric charge: coulombs (C)
• Energy: joules (J)
• Force: newtons (N)
• Temperature: kelvins (K)

Key Equations

• Newton's Second Law: F = ma (Force = mass x acceleration)
• Energy-Mass Equivalence: E = mc^2 (Energy = mass x speed of light squared)
• Wave Equation: Describes how waves propagate
• Schrödinger Equation: Describes how quantum mechanical systems change over time

Measurement and Uncertainty

• Measurements have inherent uncertainties
• Statistical analysis is used to estimate and reduce errors
• Significant figures indicate measurement precision