Classical Mechanics and Thermodynamics

Classical Mechanics

• Classical mechanics describes the motion of macroscopic objects, neglecting the effects of quantum mechanics.
• It primarily deals with Newton's laws of motion, which relate forces acting on objects to their acceleration.
• Key concepts include:
  • Newton's first law: an object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
  • Newton's second law: the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. F = ma.
  • Newton's third law: for every action, there is an equal and opposite reaction.
• Applications include: predicting the trajectory of projectiles, analyzing the motion of planets, and designing machines.

Thermodynamics

• Thermodynamics deals with the relationships between heat, work, and energy.
• Key concepts include:
  • The Zeroth Law: If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
  • The First Law: Energy cannot be created or destroyed, only transferred or changed from one form to another. (ΔU = Q – W)
  • The Second Law: The total entropy of an isolated system can only increase over time.
• Applications include: designing engines, refrigerators, and power plants; understanding phase transitions; and analyzing heat transfer processes.

Electromagnetism

• Electromagnetism describes the interaction between electric charges and magnetic fields.
• Key concepts include:
  • Electric fields: created by electric charges and exert forces on other charges.
  • Magnetic fields: created by moving electric charges and exert forces on moving charges.
• The relationship between electricity and magnetism is fundamentally interconnected and described by Maxwell's equations.
• Applications include: generating electricity, transmitting information via radio waves, and developing various electrical devices.

Optics

• Optics deals with the behavior of light.
• Key concepts include:
  • Reflection: Light bouncing off a surface.
  • Refraction: Light bending as it passes from one medium to another.
  • Diffraction: Spreading of light as it passes through an aperture or around an obstacle.
• Applications include: design of lenses, telescopes, microscopes, and other optical instruments. Understanding light allows us to study the universe and create technologies to improve our lives.

Waves

• Waves are disturbances that transport energy from one place to another without transporting matter.
• Key concepts include:
  • Types of waves: longitudinal (e.g. sound) and transverse (e.g. light).
  • Wave properties: amplitude, frequency, wavelength, period.
  • Wave interactions: interference, diffraction, reflection.
• Applications include: understanding sound, light, and other forms of energy propagation.

Modern Physics

• Modern physics extends classical physics to the atomic and subatomic level, and at high speeds approaching the speed of light.
• Key concepts include:
  • Relativity: Einstein's theories of special and general relativity, which revolutionized our understanding of space, time, gravity, and the universe.
    • Special relativity: Describes the relationship between space and time for objects moving at constant velocities.
    • General relativity: Describes gravity as a curvature of spacetime caused by mass and energy.
  • Quantum mechanics: Describes the behavior of matter and energy at the atomic and subatomic level, including phenomena such as quantization, uncertainty principle, and wave-particle duality.
• Applications include: developing nuclear energy, understanding the structure of atoms and molecules, and further explorations of the universe.