Fundamental Physics and Science Concepts Explained
Principles of Electricity and Magnetism
Fleming’s Left-Hand Rule
This rule determines the direction of the force on a current-carrying conductor within a magnetic field.
- If the index finger points in the direction of the magnetic field,
- and the middle finger points in the direction of the current,
- then the thumb indicates the direction of the force on the conductor.
Fleming’s Right-Hand Rule
Used to identify the direction of induced current when a conductor moves in a magnetic field.
- The thumb indicates
Unveiling the Cosmos: Universe, Galaxies, and Solar System
The Universe
The science that studies the Universe is astronomy.
What is the Universe (Cosmos)?
The Universe, also known as the Cosmos, is everything that exists, encompassing all matter, energy, space, and time.
Origin of the Universe: The Big Bang Theory
The most widely accepted theory regarding the origin of the Universe is the Big Bang Theory:
- Initially, all matter was concentrated in a single point with an extremely high temperature.
- Approximately 13.7 billion years ago, a colossal explosion occurred,
Fundamentals of Electricity: Quantities, Circuits, and Measurement
1 – Basic Electrical Quantities
The fundamental quantities that characterize electrical power are voltage, current, resistance, and power.
Voltage
The energy with which a generator is able to push electrons through a circuit is called voltage or electromotive force (EMF).
Voltage is also known as potential difference (PD) and is measured in volts (V).
Electric Current
Electric current is the rate of flow of electric charge through a circuit per unit time.
Electric current, also called intensity, is measured
Read MoreThe Sun’s Inner Workings: Energy, Structure, and Activity
The Sun: Our Star’s Energy, Structure, and Activity
Stellar Energy: The Power of Nuclear Fusion
Stars are powered by nuclear reactions involving hydrogen (H) and helium (He).
The source of stellar energy is nuclear fusion: the combining of lighter nuclei into heavier ones. The immense amount of energy released is described by Einstein’s famous equation: E = mc2.
The greater the nuclear binding energy, the more stable the nucleus.
Conditions for Nuclear Fusion
Nuclear fusion only occurs at temperatures
Read MoreEssential Physics Formulas and Concepts
Energy Principles and Equations
Kinetic Energy (J) = ½ × Mass (kg) × Speed (m/s)² → Ek = ½mv²
Gravitational Potential Energy (J) = Mass (kg) × Gravitational Field Strength (N/kg) × Height (m) → Ep = mgh
Elastic Potential Energy (J) = ½ × Spring Constant (N/m) × Extension² (m) → E = ½ke²
Change in Thermal Energy (J) = Mass (kg) × Specific Heat Capacity (J/kg°C) × Temperature Change (°C) → ∆E = mc∆θ
Rate of Doing Work and Power
- Power (W) = Energy Transferred (J) / Time (s)
Cosmic Foundations of Life: Astronomy & Astrobiology Concepts
The Science of Life in the Universe
- The possibility of extraterrestrial life was first considered: many thousands of years ago during ancient times.
- The methods of modern science were originated by the: Greeks.
Key Astronomical Models & Laws
- Geocentric Model
- A spherical Earth at the center of the universe, surrounded by a celestial sphere.
- Heliocentric (Sun-centered) Model
- Describes the relative motion between Earth and other planets in their orbits.
- Stellar Parallax
- The apparent shift in position of