data/knowledge_base/physics.md

Physics Knowledge Base

Classical Mechanics

Newton's Laws

• First Law: An object remains at rest or in uniform motion unless acted upon by a net force
• Second Law: F = ma (Force equals mass times acceleration)
• Third Law: For every action, there is an equal and opposite reaction

Kinematics

• Displacement: Change in position of an object
• Velocity: Rate of change of displacement (vector quantity)
• Acceleration: Rate of change of velocity
• Equations of Motion: v = u + at, s = ut + ½at², v² = u² + 2as

Dynamics

• Force: Push or pull that can change motion
• Weight: Gravitational force on an object (W = mg)
• Friction: Force opposing relative motion
• Tension: Force transmitted through strings or cables

Energy and Work

Forms of Energy

• Kinetic Energy: Energy of motion (KE = ½mv²)
• Potential Energy: Stored energy due to position
• Gravitational PE: PE = mgh (mass × gravity × height)
• Elastic PE: Energy stored in deformed objects

Work and Power

• Work: Force × displacement in direction of force
• Power: Rate of doing work (P = W/t)
• Efficiency: Useful work output / total work input
• Conservation of Energy: Energy cannot be created or destroyed

Thermodynamics

Laws of Thermodynamics

• Zeroth Law: If two systems are in thermal equilibrium with a third, they are in equilibrium with each other
• First Law: Energy cannot be created or destroyed (ΔU = Q - W)
• Second Law: Entropy of an isolated system always increases
• Third Law: Entropy approaches zero as temperature approaches absolute zero

Heat and Temperature

• Temperature: Measure of average kinetic energy
• Heat: Energy transferred due to temperature difference
• Specific Heat: Energy required to raise 1kg by 1°C
• Latent Heat: Energy for phase changes without temperature change

Waves and Oscillations

Wave Properties

• Amplitude: Maximum displacement from equilibrium
• Wavelength: Distance between consecutive peaks
• Frequency: Number of oscillations per second
• Period: Time for one complete oscillation

Types of Waves

• Transverse Waves: Oscillations perpendicular to wave direction
• Longitudinal Waves: Oscillations parallel to wave direction
• Standing Waves: Waves that appear to stand still
• Resonance: Amplitude increase at natural frequency

Electricity and Magnetism

Electric Charges

• Coulomb's Law: F = k(q₁q₂)/r²
• Electric Field: Force per unit charge
• Electric Potential: Work per unit charge
• Capacitance: Charge storage ability

Electric Current

• Ohm's Law: V = IR (Voltage = Current × Resistance)
• Power: P = VI = I²R = V²/R
• Series Circuits: Current same, voltage adds
• Parallel Circuits: Voltage same, current adds

Magnetism

• Magnetic Field: Region where magnetic forces act
• Lorentz Force: F = q(E + v×B)
• Faraday's Law: Induced EMF proportional to rate of flux change
• Lenz's Law: Induced current opposes flux change

Modern Physics

Quantum Mechanics

• Wave-Particle Duality: Matter exhibits both wave and particle properties
• Heisenberg Uncertainty: Cannot simultaneously know position and momentum exactly
• Quantum Tunneling: Particles can pass through energy barriers
• Superposition: Quantum systems can exist in multiple states simultaneously

Relativity

• Special Relativity: E = mc², time dilation, length contraction
• General Relativity: Gravity as curvature of spacetime
• Mass-Energy Equivalence: Mass and energy are interchangeable
• Spacetime: Four-dimensional fabric of universe

Optics

Light Properties

• Reflection: Light bouncing off surfaces
• Refraction: Light bending when changing medium
• Diffraction: Light bending around obstacles
• Interference: Light waves combining constructively or destructively

Lenses and Mirrors

• Convex Lens: Converges light rays
• Concave Lens: Diverges light rays
• Focal Length: Distance from lens to focal point
• Magnification: Ratio of image to object size