Physics Fundamentals

Mechanics

Kinematics

• Study of motion without considering forces
• Key concepts:
  • Displacement (distance from initial to final position)
  • Velocity (rate of change of displacement)
  • Acceleration (rate of change of velocity)
  • Time

Dynamics

• Study of motion considering forces
• Key concepts:
  • Force (push or pull that causes motion)
  • Newton's Laws:
    • 1st Law (Inertia): object at rest stays at rest, object in motion stays in motion
    • 2nd Law (F = ma): force equals mass times acceleration
    • 3rd Law (Action and Reaction): every action has an equal and opposite reaction

Energy and Work

• Key concepts:
  • Kinetic energy (energy of motion)
  • Potential energy (stored energy)
  • Work (force times displacement)
  • Conservation of Energy: energy cannot be created or destroyed, only converted

Thermodynamics

Laws of Thermodynamics

• Key concepts:
  • Zeroth Law: if two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other
  • First Law (Conservation of Energy): energy cannot be created or destroyed, only converted
  • Second Law: total entropy (disorder or randomness) always increases over time
  • Third Law: as temperature approaches absolute zero, entropy approaches a minimum value

Thermodynamic Systems

• Key concepts:
  • Isolated system: no energy or matter can enter or leave
  • Closed system: energy can enter or leave, but not matter
  • Open system: both energy and matter can enter or leave
  • Thermal equilibrium: systems in contact with each other have the same temperature

Electromagnetism

Electric Charges and Fields

• Key concepts:
  • Electric charge: fundamental property of matter
  • Electric field: force per unit charge around a charge or group of charges
  • Coulomb's Law: force between two charges is proportional to the product of the charges and inversely proportional to the square of the distance between them

Electric Circuits

• Key concepts:
  • Electric current: flow of electric charge
  • Resistance: opposition to electric current
  • Ohm's Law: voltage equals current times resistance

Electromagnetic Waves

• Key concepts:
  • Electromagnetic waves: waves that propagate through electromagnetic fields
  • Electromagnetic spectrum: range of frequencies from low-energy radio waves to high-energy gamma rays
  • Speed of light: constant speed at which electromagnetic waves propagate in a vacuum