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All Physics Articles
40 original articles across six branches — each with clear explanations, key formulas, a worked example, common mistakes and practice questions.
⚙️ Classical Mechanics
Forces, energy, momentum and motion.
Circular Motion and Centripetal Force
Circular motion needs a centre-seeking force: centripetal force, F = mv²/r. Learn why objects turn, what supplies the force, and how to calculate it.
Conservation of Momentum
Momentum is conserved when no external force acts: momentum before equals momentum after. Learn the rule, p = mv, and collision examples.
Friction: Static, Kinetic and Rolling
Friction opposes motion between surfaces. Learn static, kinetic and rolling friction, the formula F = μN, and where friction helps or hurts.
Newton's First Law of Motion
Newton's first law explains inertia: objects keep their motion unless a net force acts. Learn what it means, with everyday examples and practice questions.
Newton's Second Law of Motion
Newton's second law links force, mass and acceleration with F = ma. Learn how to use it, what each symbol means, and how to solve problems with it.
Newton's Third Law of Motion
Newton's third law says every action has an equal and opposite reaction. Learn why forces always come in pairs and why they never cancel each other out.
Work and the Work–Energy Theorem
Work is force times distance, and the work-energy theorem says net work equals the change in kinetic energy. Learn the formulas and how to use them.
📐 Kinematics
Describing motion: velocity, acceleration and trajectories.
Acceleration Explained
Acceleration is the rate of change of velocity. Learn what it means, how to calculate it with a = Δv/t, and why slowing down and turning count too.
Free Fall and Gravity
In free fall, gravity alone acts and every object accelerates at g = 9.81 m/s². Learn the equations of falling motion, with worked examples and air resistance.
Projectile Motion Basics
A projectile follows a curved path: steady horizontal motion plus accelerating vertical motion. Learn to split the motion and find range and height.
Relative Velocity
Relative velocity is how fast something moves as seen from another moving object. Learn to add and subtract velocities, with trains and rivers.
Terminal Velocity
Terminal velocity is the steady fastest speed a falling object reaches when air resistance balances its weight. Learn why it happens and what changes it.
The SUVAT Equations of Motion
SUVAT is the set of five equations for motion with constant acceleration. Learn what each letter means, when to use each equation, and how to solve problems.
Velocity vs Speed: What's the Difference?
Speed is how fast; velocity is how fast in which direction. Learn the difference between these two quantities, with examples, formulas and practice questions.
⚡ Electromagnetism
Charge, current, fields, circuits and magnetism.
Capacitors and Capacitance
Understand capacitors, capacitance, how they store charge and energy, and why they are used in circuits from camera flashes to power supplies.
Electric Charge and Coulomb's Law
Learn what electric charge is, how Coulomb's law predicts the force between charges, and why like charges repel and opposite charges attract.
Electric Fields and Electric Potential
Understand electric fields, electric potential and voltage, how they are related, and how to calculate field strength around a point charge.
Electromagnetic Induction and Faraday's Law
Learn how a changing magnetic field induces a voltage, Faraday's law and Lenz's law, and how generators and transformers work.
Magnetism: Fields, Forces and Compasses
Discover magnetic fields, how magnets and moving charges create them, the force on a current-carrying wire, and how a compass works.
Ohm's Law and Electric Circuits
Learn Ohm's law, how voltage, current and resistance relate, and how to calculate power and analyse simple series and parallel circuits.
The Electromagnetic Spectrum
Explore the electromagnetic spectrum from radio waves to gamma rays, how wavelength and frequency relate, and what each region is used for.
🔥 Thermodynamics
Heat, temperature, energy and entropy.
Entropy Explained
Learn what entropy is, why disorder tends to increase, and how the second law of thermodynamics limits engines and every real process.
Heat Transfer: Conduction, Convection, Radiation
Learn the three ways heat moves: conduction through solids, convection in fluids, and radiation through empty space, with everyday examples.
Temperature, Heat and Thermal Energy
Learn the difference between temperature, heat and thermal energy, how thermometers work, and how heat flows from hot to cold.
The Carnot Cycle and Heat Engines
Learn the Carnot cycle, the most efficient possible heat engine, how its efficiency depends on temperature, and why no real engine can beat it.
The First Law of Thermodynamics
Learn the first law of thermodynamics: energy is conserved, and how heat, work and internal energy are connected in any process.
The Ideal Gas Law
Learn the ideal gas law, how pressure, volume, temperature and amount of gas relate, and when real gases stop behaving ideally.
🌊 Waves & Optics
Waves, sound, light, lenses and interference.
Interference and Diffraction
Learn how waves interfere, what diffraction is, why double-slit fringes form, and how diffraction limits the detail of any optical instrument.
Lenses and Mirrors
Learn how lenses and mirrors form images, the lens and mirror equations, magnification, and how glasses, cameras and telescopes work.
Reflection and Refraction of Light
Learn how light reflects and refracts, the laws of reflection, Snell's law, and why a straw looks bent in a glass of water.
Sound Waves
Learn how sound travels as a longitudinal wave, what pitch and loudness mean, the speed of sound, and how echoes and ultrasound work.
The Doppler Effect
Learn the Doppler effect, why a siren changes pitch as it passes, the formula for a moving source, and how astronomers use redshift.
Waves: Amplitude, Frequency and Wavelength
Learn what waves are, amplitude, frequency, wavelength and period, how wave speed is calculated, and the difference between transverse and longitudinal waves.
⚛️ Modern Physics
Quantum mechanics, relativity, atoms and beyond.
Quantum Computing Basics: Qubits and Superposition
Learn the basics of quantum computing: qubits, superposition, entanglement and measurement, and what quantum computers can and cannot do.
Quantum Mechanics: An Introduction
An introduction to quantum mechanics: wave-particle duality, quantisation, uncertainty and why the quantum world does not behave like everyday objects.
Radioactivity and Half-Life
Learn what radioactivity is, alpha, beta and gamma decay, half-life, and how radioactive decay is used in medicine, dating and power.
Relativity: Time Dilation and Length Contraction
Learn Einstein's relativity: time dilation, length contraction, mass-energy equivalence, and why the speed of light is the same for everyone.
Superconductivity Explained
Learn what superconductivity is, zero resistance, the Meissner effect, critical temperature, and where superconductors are used today.
The Bohr Model of the Atom
Learn the Bohr model of the atom, quantised electron orbits, energy levels, and how it explains the spectral lines of hydrogen.
The Photoelectric Effect
Learn the photoelectric effect, how light ejects electrons from a metal, Einstein's photon explanation, and the equation KE = hf - phi.