Introduction to Physics

• Physics is a natural science concerning matter, its constituents, motion, and behavior through space-time, along with energy and force.
• Physics aims to understand the behavior of the universe

Core Concepts

• Mechanics involves the motion of objects and the forces behind it
• Thermodynamics explores heat and its connection to other energy forms
• Electromagnetism covers interactions between electric currents/fields and magnetic fields
• Optics studies light and its behavior
• Quantum mechanics studies matter and energy at the atomic and subatomic level

Mechanics

• Kinematics describes motion without considering forces
• Dynamics concerns the forces affecting motion
• Newton's Laws of Motion are as follows:
  • First Law: Objects at rest stay at rest, and objects in motion stay in motion with the same speed and direction unless acted upon by a force.
  • Second Law: Object acceleration is proportional to net force, in the same direction, and inversely proportional to mass (F = ma).
  • Third Law: Every action has an equal and opposite reaction.
• Work and Energy are calculated as:
  • Work refers to energy transferred by a force acting on an object (W = Fdcosθ)
  • Kinetic Energy is the energy of motion (KE = 1/2 mv^2)
  • Potential Energy is the energy of position or condition
• Conservation of Energy dictates that total energy in an isolated system remains constant

Thermodynamics

• Temperature measures the average kinetic energy of atoms/molecules in a system
• Heat is the transfer of energy due to temperature differences
• Laws of Thermodynamics are as follows:
  • Zeroth Law: Systems in thermal equilibrium with a third system are in thermal equilibrium with each other
  • First Law: Change in internal energy equals heat added minus work done (ΔU = Q - W)
  • Second Law: Entropy in an isolated system increases or remains constant
  • Third Law: Entropy approaches a constant value as temperature nears absolute zero
• Heat Transfer occurs through conduction, convection, and radiation

Electromagnetism

• Electric Charge is a fundamental property causing matter to experience force in an electromagnetic field
• Electric Field is the region around a charged object exerting force on other charged objects
• Electric Potential is electric potential energy per unit charge in an electric field
• Capacitance refers to the ability to store electrical charge
• Electric Current is the rate of electric charge flow
• Magnetic Field is a force field produced by moving electric charges
• Electromagnetism Induction is the production of electromotive force across a conductor in a changing magnetic field
• Maxwell's Equations describe electric and magnetic field behavior

Optics

• Reflection is the change in wave direction at an interface, returning the wave to its origin medium
• Refraction is the change in wave direction as it transitions between media
• Lenses focus or disperse light via refraction
• Interference involves wave superposition, creating a new wave pattern
• Diffraction is the bending of waves around obstacles or through apertures
• Polarization is the alignment of light wave electric field vectors

Quantum Mechanics

• Quantum represents the smallest amount of a physical entity in an interaction
• Wave-particle duality states that elementary particles/entities exhibit both particle and wave properties
• Heisenberg Uncertainty Principle says it's impossible to perfectly measure both position and momentum
• Quantum Entanglement is when quantum states of two or more objects are linked, so one can't be described without the other, even when separated
• Schrödinger Equation describes how a physical system's quantum state changes over time