Classical Mechanics and Thermodynamics

Classical Mechanics

• Classical mechanics describes the motion of macroscopic objects, such as planets, cars, and balls.
• It's based on Newton's laws of motion.
• Key concepts include:
  • Force: A push or pull that can change an object's motion.
  • Mass: A measure of an object's inertia (resistance to acceleration).
  • Acceleration: The rate of change of an object's velocity.
  • 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: Calculating trajectories, predicting motion, and analyzing forces in various physical systems.

Thermodynamics

• Thermodynamics studies the relationships between heat, work, and energy.
• Key concepts include:
  • Temperature: A measure of the average kinetic energy of the particles in a substance.
  • Heat: Energy transferred between objects due to a temperature difference.
  • Work: Energy transferred to or from an object by a force acting through a distance.
  • Internal energy: The total energy of the particles within a system.
  • Zeroth law: If two systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
  • First law: Energy can be transferred and transformed, but it cannot be created or destroyed. (ΔU=Q-W)
  • Second law: The total entropy of an isolated system can never decrease over time.
  • Third law: The entropy of a perfect crystal at absolute zero temperature is zero.
• Applications: Designing engines, understanding phase transitions, and analyzing heat transfer in various systems.

Electromagnetism

• Electromagnetism describes the interactions between electric charges and magnetic fields.
• Key concepts include:
  • Electric charge: A fundamental property of matter that causes electric forces.
  • Electric field: A region of space where an electric charge experiences a force.
  • Magnetic field: A region of space where a moving electric charge or a magnetic dipole experiences a force.
  • Coulomb's law: The force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
  • Ampere's law: The magnetic field around a current-carrying wire is proportional to the current.
  • Faraday's law: A changing magnetic field induces an electromotive force (voltage) in a conductor.
• Applications: Generating electricity, designing motors, and understanding electromagnetic waves.

Optics

• Optics studies the behavior of light.
• Key concepts include:
  • Reflection: The bouncing of light off a surface.
  • Refraction: The bending of light as it passes from one medium to another.
  • Diffraction: The spreading of light as it passes through an opening or around an obstacle.
  • Interference: The combination of two or more light waves to produce a resultant wave.
  • Total Internal Reflection: The phenomenon where light is completely reflected at the boundary between two media when it travels from a denser to a rarer medium at an angle greater than the critical angle.
• Applications: Designing telescopes, microscopes, and lenses. Understanding phenomena like rainbows and mirages.

Modern Physics

• Modern physics encompasses principles and theories developed in the 20th century, like quantum mechanics and relativity.
• Key concepts include:
  • Quantum mechanics: Describes the behavior of matter and energy at the atomic and subatomic level. Quantum mechanics introduces concepts such as quantized energy levels and wave-particle duality.
  • Special relativity: Describes space and time as a unified four-dimensional entity and the relationship between space and time, depending on the observer's relative speed.
  • General relativity: Describes gravity as a curvature of spacetime caused by mass and energy.
• Applications: Developing technologies like lasers, nuclear energy, and understanding the behavior of elementary particles.