Key Concepts in Physics

Basic Principles
- Newton's Laws of Motion
  - 1st Law: An object in motion stays in motion unless acted upon by an external force.
  - 2nd Law: F = ma (Force = mass × acceleration).
  - 3rd Law: For every action, there is an equal and opposite reaction.
- Conservation Laws
  - Conservation of Energy: Energy cannot be created or destroyed, only transformed.
  - Conservation of Momentum: Total momentum in a closed system remains constant.
Forces and Interactions
- Types of Forces:
  - Gravitational: Attraction between masses.
  - Electromagnetic: Attraction/repulsion between charged particles.
  - Nuclear: Strong and weak forces within an atom.
Energy Types
- Kinetic Energy: Energy of motion (KE = 1/2 mv²).
- Potential Energy: Stored energy due to position (PE = mgh for gravitational).
- Thermal Energy: Internal energy due to temperature.
Waves and Oscillations
- Mechanical Waves: Require a medium (e.g., sound waves).
- Electromagnetic Waves: Do not require a medium (e.g., light waves).
- Wave Properties: Wavelength, frequency, amplitude, speed.
Thermodynamics
- Laws of Thermodynamics:
  - 1st Law: Energy conservation.
  - 2nd Law: Entropy of an isolated system always increases.
  - 3rd Law: As temperature approaches absolute zero, entropy approaches a constant minimum.
Electricity and Magnetism
- Ohm's Law: V = IR (Voltage = Current × Resistance).
- Circuit Types: Series and parallel circuits.
- Magnetic Fields: Produced by moving charges; follow the right-hand rule.
Modern Physics
- Quantum Mechanics: Behavior of particles at atomic and subatomic levels.
- Relativity: Einstein's theories altering views on space, time, and gravity.
  - Special Relativity: Speed of light is constant; time dilation.
  - General Relativity: Gravity is a curvature of spacetime.
Units of Measurement
- SI Units: Standard units for measurement in physics.
  - Mass: kilogram (kg)
  - Length: meter (m)
  - Time: second (s)
  - Force: Newton (N)
  - Energy: Joule (J)
Applications of Physics
- Engineering: Application of physics principles to design technologies.
- Medicine: Use of physics in imaging techniques (e.g., MRI, X-rays).
- Environmental Science: Understanding physical processes in climate and ecosystems.

Basic Principles

Newton's Laws of Motion
- 1st Law: An object in motion remains in motion unless acted upon by an external force.
- 2nd Law: Defines force as the product of mass and acceleration (F = ma).
- 3rd Law: For every action, there is an equal and opposite reaction.
Conservation Laws
- Conservation of Energy: Energy cannot be created or destroyed; it can only be transformed from one form to another.
- Conservation of Momentum: In a closed system, total momentum remains constant irrespective of interactions within the system.

Forces and Interactions

Types of Forces
- Gravitational: Describes the attraction between masses.
- Electromagnetic: Involves attraction and repulsion between charged particles.
- Nuclear: Comprises strong and weak forces operating within atomic nuclei.

Energy Types

Kinetic Energy: Energy possessed by an object in motion, calculated using KE = 1/2 mv².
Potential Energy: Energy stored due to an object's position, with gravitational potential energy defined as PE = mgh.
Thermal Energy: Energy related to the internal temperature of an object.

Waves and Oscillations

Mechanical Waves: Require a medium for propagation, such as sound waves traveling through air.
Electromagnetic Waves: Can travel through a vacuum, illustrated by light waves.
Wave Properties: Key characteristics include wavelength, frequency, amplitude, and speed.

Thermodynamics

Laws of Thermodynamics
- 1st Law: Energy in a closed system is conserved.
- 2nd Law: Entropy of an isolated system will always increase over time.
- 3rd Law: As temperature approaches absolute zero, the entropy approaches a constant minimum.

Electricity and Magnetism

Ohm's Law: Voltage (V) is the product of current (I) and resistance (R), expressed as V = IR.
Circuit Types: Circuits can be arranged in series or parallel, affecting current and voltage distribution.
Magnetic Fields: Generated by moving electric charges and can be determined using the right-hand rule.

Modern Physics

Quantum Mechanics: Studies the behavior and interactions of particles at atomic and subatomic levels.
Relativity: Einstein's theories revolutionized concepts of space, time, and gravity.
- Special Relativity: Establishes the constancy of the speed of light and introduces time dilation.
- General Relativity: Explains gravity as the warping of spacetime around mass.

Units of Measurement

SI Units: Standardized units used for measurement in physics, including:
- Mass: kilogram (kg)
- Length: meter (m)
- Time: second (s)
- Force: Newton (N)
- Energy: Joule (J)

Applications of Physics

Engineering: Utilizes physics concepts to innovate and enhance technological designs.
Medicine: Implements physics principles for diagnostic imaging technologies like MRI and X-rays.
Environmental Science: Analyzes physical phenomena to understand climate dynamics and ecosystem processes.