Key Concepts in Physics

Classical Mechanics
- Studies the motion of bodies under the influence of forces.
- Key principles include Newton's laws of motion.
- Concepts of energy, work, momentum, and conservation laws.
Thermodynamics
- Focuses on heat transfer and the laws governing energy.
- Key laws:
  - Zeroth Law: Thermal equilibrium.
  - First Law: Conservation of energy.
  - Second Law: Entropy and direction of processes.
  - Third Law: Absolute zero and entropy.
Electromagnetism
- Studies electric and magnetic fields and their interactions.
- Key concepts include:
  - Coulomb's law: Force between electric charges.
  - Faraday's law: Induction of electric currents.
  - Maxwell's equations: Foundation of electromagnetism.
Waves and Oscillations
- Examines oscillatory motion and wave phenomena.
- Types of waves:
  - Mechanical vs. electromagnetic waves.
  - Transverse vs. longitudinal waves.
- Key terms: frequency, wavelength, amplitude, and speed.
Optics
- Study of light and its properties.
- Key concepts include:
  - Reflection and refraction.
  - Lenses and mirrors.
  - Dispersion and polarization.
Modern Physics
- Encompasses theories developed in the 20th century.
- Key areas include:
  - Quantum mechanics: Behavior of particles at atomic scales.
  - Relativity: Effects of gravity and motion at high speeds (Einstein's theories).
  - Particle physics: Study of fundamental particles and forces.
Astrophysics
- Application of physics to understand astronomical phenomena.
- Key topics include:
  - Structure and dynamics of stars, galaxies, and the universe.
  - Cosmology: Study of the universe's origin, evolution, and fate.

Fundamental Units of Measurement

SI Units
- Length: meter (m)
- Mass: kilogram (kg)
- Time: second (s)
- Electric current: ampere (A)
- Temperature: kelvin (K)
- Amount of substance: mole (mol)
- Luminous intensity: candela (cd)

Important Formulas

Kinematics
- ( v = u + at ) (Velocity formula)
- ( s = ut + \frac{1}{2}at^2 ) (Displacement formula)
Newton's Second Law
- ( F = ma ) (Force equals mass times acceleration)
Work and Energy
- ( W = Fd \cos(\theta) ) (Work done by a force)
- ( KE = \frac{1}{2}mv^2 ) (Kinetic energy)
- ( PE = mgh ) (Potential energy)
Ohm's Law
- ( V = IR ) (Voltage equals current times resistance)

Branches of Physics

Mechanics
Thermodynamics
Electromagnetism
Optics
Acoustics
Nuclear Physics
Astrophysics
Condensed Matter Physics

Key Concepts in Physics

Classical Mechanics
- Analyzes the motion of objects influenced by forces, based on Newton's laws of motion.
- Involves concepts of energy (kinetic and potential), work, momentum, and conservation principles.
Thermodynamics
- Studies heat transfer and energy regulation via fundamental laws.
- Zeroth Law: Establishes thermal equilibrium conditions.
- First Law: States energy conservation; energy cannot be created or destroyed.
- Second Law: Introduces entropy; explains spontaneous processes and energy distribution.
- Third Law: Defines absolute zero and its relationship with entropy.
Electromagnetism
- Investigates electric and magnetic fields and their interactions.
- Coulomb’s Law describes the electrostatic force between charged bodies.
- Faraday’s Law outlines the induction of electric currents through changing magnetic fields.
- Maxwell's Equations serve as the foundation for electromagnetism, linking electricity and magnetism.
Waves and Oscillations
- Focuses on oscillatory motion and various wave phenomena.
- Distinguishes between mechanical waves (require a medium) and electromagnetic waves (can travel through vacuum).
- Differentiates between transverse waves (oscillation perpendicular to direction) and longitudinal waves (oscillation parallel to direction).
- Key terms include frequency (how often a wave occurs), wavelength (distance between waves), amplitude (maximum displacement), and speed (how fast wave travels).
Optics
- Explores the behavior of light and its various properties.
- Key concepts include reflection (bouncing off surfaces) and refraction (bending as it passes into different mediums).
- Involves the study of lenses (focus light) and mirrors (reflect light) along with dispersion (separation of colors) and polarization (filtering light waves).
Modern Physics
- Encompasses theories arising in the 20th century, revolutionizing our understanding of physics.
- Quantum mechanics deals with particles' behavior at atomic and subatomic levels.
- Relativity, proposed by Einstein, examines the effects of gravity and the behavior of objects at high velocities.
- Particle physics studies fundamental particles and the forces governing them.
Astrophysics
- Applies principles of physics to analyze celestial phenomena and structures.
- Covers the formation and dynamics of stars, galaxies, and the universe.
- Cosmology focuses on the universe's origin, development, and ultimate fate.

Fundamental Units of Measurement

SI Units essential for quantitative measurement:
- Length: meter (m)
- Mass: kilogram (kg)
- Time: second (s)
- Electric current: ampere (A)
- Temperature: kelvin (K)
- Amount of substance: mole (mol)
- Luminous intensity: candela (cd)

Important Formulas

Kinematics
- ( v = u + at ): Calculates final velocity based on initial velocity (u), acceleration (a), and time (t).
- ( s = ut + \frac{1}{2}at^2 ): Determines displacement over time for uniformly accelerated motion.
Newton's Second Law
- ( F = ma ): Describes the relationship between force (F), mass (m), and acceleration (a).
Work and Energy
- ( W = Fd \cos(\theta) ): Work done by a force, considering the angle (θ) between force direction and displacement.
- ( KE = \frac{1}{2}mv^2 ): Formula for kinetic energy of an object.
- ( PE = mgh ): Calculates gravitational potential energy based on mass (m), gravitational acceleration (g), and height (h).
Ohm's Law
- ( V = IR ): Relates voltage (V), current (I), and resistance (R) in electrical circuits.

Branches of Physics

Mechanics: Study of motion and forces.
Thermodynamics: Exploration of energy transfer and heat.
Electromagnetism: Examination of electric and magnetic fields.
Optics: Investigation of light behavior.
Acoustics: Study of sound and its propagation.
Nuclear Physics: Focus on atomic nuclei and nuclear reactions.
Astrophysics: Relationship between physics and astronomical phenomena.
Condensed Matter Physics: Investigates the properties of solid and liquid materials.