Subjects
Physics
Mechanics, thermodynamics, electricity — master the laws that govern our universe.
See all (133)
AC Circuit Analysis — Impedance and Phasors
AC circuit analysis explained clearly: what impedance and phasors mean, when the method works, and one series RC example.
Acceleration Formulas
Learn the main acceleration formula, when constant-acceleration equations apply, one worked example, and the mistakes that cause the most confusion.
Amplitude and Frequency
Learn what amplitude and frequency mean in physics, how they differ, and how to find each from a simple wave example.
Angular Momentum
Learn what angular momentum means, when to use its main formulas, and how one worked example makes the idea easier to use.
AP Physics — Mechanics, E&M & Key Formulas
Understand AP Physics fast with key mechanics and E&M formulas, when they work, and how to choose the right model.
Archimedes' Principle — Buoyancy Formula & Examples
Archimedes' principle explained clearly: what buoyant force means, the buoyancy formula, one worked example, and common mistakes.
Astronomy Basics: Stars, Galaxies, Black Holes, and the Universe
Astronomy basics explained: what stars, galaxies, black holes, and the universe are, plus how astronomers use light to study space.
Beam Deflection Formula
Learn what the beam deflection formula means, when $PL^3/(3EI)$ applies, and how to work one cantilever example correctly.
Bernoulli's Equation
Learn what Bernoulli's equation means, when the simple form applies, and how pressure changes when fluid speed changes.
Capacitors — Capacitance, Types & Circuits
What capacitors do, what capacitance means, how common types differ, and how ideal capacitors behave in basic circuits.
Carnot Cycle
Learn what the Carnot cycle is, how its four stages work, and how to find the maximum possible heat-engine efficiency.
Celsius to Fahrenheit — Temperature Conversion Formula
Learn the Celsius to Fahrenheit formula, why the offset matters, and how to convert one temperature correctly with a clear example.
Centripetal Force
Learn what centripetal force is, why it points inward, and how to use the formula in one clear circular-motion example.
Column Buckling - Euler's Formula
Understand Euler's column buckling formula, when it applies, how effective length changes the load, and one clear worked example.
Conservation of Momentum — Elastic & Inelastic Collisions
Understand conservation of momentum, when it applies, and how elastic and inelastic collisions work through one clear example.
Coulomb's Law — Electric Force Formula & Examples
Coulomb's law explains the electric force between two charges. Learn the formula, when it applies, and how to solve a clear example.
De Broglie Wavelength — Matter Wave Formula & Examples
Understand the de Broglie wavelength, the matter-wave formula lambda = h/p, and a clear electron example.
Dimensional Analysis
Understand dimensional analysis in physics: what it is, how to check equations, and one clear example of finding a formula's form.
Doppler Effect — Formula for Sound & Light
Learn the Doppler effect fast: what changes, the sound formula, the relativistic light formula, one clear ambulance example, and the mistakes to avoid.
Earth Science — Geology, Weather, Oceans & Atmosphere
Earth science explained simply: what geology, weather, oceans, and the atmosphere study, how they connect, and one clear example.
Earth's Layers — Crust, Mantle, Core Structure
Earth's layers explained clearly: crust, mantle, outer core, and inner core, plus how seismic waves show the outer core is liquid.
Elasticity — Stress, Strain, Young's Modulus & Hooke's Law
Learn what elasticity means, how stress and strain differ, when Hooke's law applies, and how Young's modulus predicts extension.
Electric Field
Understand electric field as force per unit charge, when $E = k |Q| / r^2$ applies, and how to solve one clear example.
Electric Potential — Voltage, Potential Energy & Equipotential
Learn what electric potential means, how voltage relates to potential energy, and why equipotential lines make electric fields easier to read.
Electricity — Current, Voltage, Resistance & Power
Understand current, voltage, resistance, and power fast, with one clear circuit example and the mistakes beginners often make.
Electromagnetic Induction
Understand electromagnetic induction, why changing magnetic flux creates induced emf, and how to solve one clear example.
Electromagnetic Spectrum — Wavelengths, Frequencies & Uses
Understand the electromagnetic spectrum fast: the order from radio waves to gamma rays, the wavelength-frequency relation, one example, and common uses.
Entropy — Definition, Formula & Second Law Connection
Learn what entropy means in physics, when formulas like $dS = \\delta Q_{rev}/T$ and $S = k_B \\ln \\Omega$ apply, and how entropy connects to the second law.
Fahrenheit to Celsius — F to C Conversion
Convert Fahrenheit to Celsius with the correct formula, one worked example, and the key mistake to avoid.
Faraday's Law — Electromagnetic Induction & Lenz's Law
Understand Faraday's law: how changing magnetic flux induces emf, how Lenz's law gives direction, and how to solve a standard example.
Fatigue Failure — S-N Curve
Learn what an S-N curve shows, how to estimate fatigue life, when endurance limit applies, and the common mistakes students make.
Fluid Dynamics: Navier-Stokes, Reynolds Number, and Turbulence
Fluid dynamics explained simply: what Navier-Stokes means, how Reynolds number works, and why turbulence appears.
Force and Motion — Newton's Laws Made Simple
Understand force and motion with Newton's laws, net force, one clear example, and the mistakes that confuse many students.
Free Body Diagram
Learn what a free-body diagram is, how to draw one step by step, and how to avoid the most common mistakes in physics problems.
Friction — Types, Formula & Real-World Examples
Learn what friction means in physics, when to use static or kinetic friction, and how to solve a simple friction-force example.
Gauss's Law — Electric Flux & Applications
Gauss's law relates electric flux to enclosed charge. Learn the formula, the intuition, one worked example, and common mistakes.
Gravity — Newton's Law of Universal Gravitation
Gravity means masses attract. Learn Newton's law, when $F = G m_1 m_2 / r^2$ applies, and why distance changes force so much.
Half-Life — Radioactive Decay Formula & Examples
Half-life explained in plain language: what it means, when the radioactive decay formula applies, one worked example, and common mistakes.
Hamiltonian Mechanics — Phase Space & Hamilton's Equations
Hamiltonian mechanics explained: what phase space is, how Hamilton's equations work, and one clear harmonic-oscillator example.
Heat Exchanger — Types and Design
Heat exchanger design explained with common types, flow patterns, LMTD, and one clear sizing example.
Heat Transfer — Conduction, Convection & Radiation
Heat transfer is energy moving from hot to cold. Learn conduction, convection, and radiation with one clear example and common mistakes.
Heisenberg Uncertainty Principle — Formula & Significance
Heisenberg uncertainty principle explained: what $\Delta x \Delta p \ge \hbar/2$ means, one example, common mistakes, and why it matters.
Hooke's Law — F = kx, Spring Constant & Examples
Learn what Hooke's law means, when $F = kx$ works, what the spring constant measures, and how to solve one clear spring example.
Inductors — Inductance, RL Circuits & Energy Storage
Learn what an inductor does, how RL circuits respond, and how magnetic energy storage works.
Interference & Diffraction — Young's Experiment & Patterns
Learn the difference between interference and diffraction, how Young's double-slit experiment makes fringes, and how fringe spacing is found.
JEE Physics — Key Topics, Formulas & Strategy
Understand JEE Physics fast with the core topics, key formulas with conditions, one solved example, common mistakes, and a practical study plan.
Kinematic Equations — The 4 SUVAT Formulas Explained
Learn the four standard kinematic equations, what the symbols mean, when the formulas work, and how to use them in one clear example.
Kinetic Energy Formula
Learn the kinetic energy formula, when it applies in classical physics, and how to use it in one clear example.
Kirchhoff's Current Law (KCL)
Learn Kirchhoff's Current Law, why current balances at a node, and how to solve one simple KCL example step by step.
Kirchhoff's Laws — KCL & KVL Explained with Examples
Learn what Kirchhoff's current law and voltage law mean, when they apply, one worked circuit example, common mistakes, and where they are used.
Kirchhoff's Voltage Law (KVL)
Understand Kirchhoff's Voltage Law quickly, including what it means, when it applies, and how to use it in a simple loop example.
Lagrangian Mechanics — Euler-Lagrange Equation & Examples
Lagrangian mechanics explained clearly: what the Euler-Lagrange equation means, when L = T - V works, and one pendulum example.
Laws of Thermodynamics — 0th, 1st, 2nd & 3rd Laws
Understand the 0th, 1st, 2nd, and 3rd laws of thermodynamics with plain-language intuition, one worked example, and common mistakes.
Lens Equation (Thin Lens)
Understand the thin lens equation, when it applies, how sign convention affects the answer, and one clear image-distance example.
Lenz's Law — Direction of Induced Current
Learn how Lenz's law gives the direction of induced current, with one clear magnet-and-loop example and the main mistakes to avoid.
Light — Speed, Reflection, Refraction & Spectrum
Learn what light is in physics, why it reflects and refracts, how fast it travels, and where the visible spectrum fits.
Magnetic Field — Sources, Properties & Right-Hand Rule
Understand what a magnetic field is, where it comes from, how its direction works, and how to use the right-hand rule in one clear wire example.
Magnets — Poles, Magnetic Fields & Electromagnets
Learn what magnets are, how magnetic poles and fields work, and why electromagnets need current in one clear example.
Maxwell's Equations — The 4 Laws of Electromagnetism
Maxwell's equations explain how electric and magnetic fields relate to charge and current, with one clear example and common mistakes.
Mohr's Circle — Stress Analysis
Understand Mohr's circle for plane stress, find principal stresses and maximum in-plane shear stress, and follow one worked example.
Moment of Inertia — Formulas and Examples
Moment of inertia measures how strongly an object resists changes in rotation about a chosen axis. Learn the key formulas and one clear example.
Momentum — Formula, Conservation & Impulse
Momentum explained clearly: what $p = mv$ means, when momentum is conserved, how impulse changes momentum, and one worked example.
MPH to KM/H — Speed Unit Conversion
Convert mph to km/h by multiplying by 1.609344. See why the factor works, a worked example, and common mistakes to avoid.
Newton's First Law (Inertia)
Learn Newton's first law fast: what inertia means, when zero net force gives constant velocity, and the mistakes students often make.
Newton's Laws of Motion — First, Second & Third Law
Understand Newton's three laws of motion fast, with plain-language definitions, one worked example, common mistakes, and where each law is used.
Newton's Second Law
Learn Newton's second law, when $F_{net} = ma$ applies, and how force and mass change acceleration in an interactive simulator.
Newton's Third Law (Action-Reaction)
Learn Newton's third law, why action-reaction forces act on different objects, and how to identify force pairs fast.
Norton's Theorem
Learn what Norton's theorem means, when the Norton equivalent applies, how to find the source current and resistance, and how to use one worked example.
Nuclear Fission and Fusion
Understand the difference between nuclear fission and fusion, why both can release energy, one clear binding-energy example, and the mistakes that cause confusion.
Nuclear Fission vs Fusion — Differences & Energy
Learn the difference between nuclear fission and fusion, why both can release energy, and where each process is used in one clear explainer.
Ohm's Law — V = IR Formula, Examples & Calculator
Learn Ohm's law fast: what V = IR means, when it works, one clear example, common mistakes, and where the formula is used.
Ohm's Law Calculator
Learn how an Ohm's law calculator uses $V = IR$ to find voltage, current, or resistance, when it applies, and the mistakes to avoid.
Op-Amp Circuits — Basics
Learn op-amp circuit basics: when the ideal rules apply, how inverting and non-inverting amplifiers work, and the mistakes to avoid.
Optics — Reflection, Refraction & Lenses
Learn optics fast: reflection, refraction, thin lenses, one worked example, and the mistakes that confuse most students.
Oscillations — SHM, Damped & Forced Oscillations
Learn what oscillations are in physics, how SHM differs from damped and forced motion, and why resonance matters in one spring example.
Pascal's Law — Hydraulic Press & Fluid Pressure
Learn Pascal's law fast: what it means, when the hydraulic press formula works, one clear example, and common mistakes.
Pendulum — Period, Frequency & Simple Harmonic Motion
Learn what a pendulum is, when its motion is approximately simple harmonic, how period and frequency are found, and how to avoid the most common mistakes.
Photoelectric Effect — Einstein's Equation & Applications
Photoelectric effect explained clearly: what Einstein's equation means, why threshold frequency matters, one worked example, and common mistakes.
PID Controller — Explained
Understand what a PID controller does, what the P, I, and D terms mean, and how one worked example shows the idea in practice.
Plate Tectonics — Boundaries, Movement & Earthquakes
Plate tectonics explained clearly: what tectonic plates are, how boundaries work, and why earthquakes and volcanoes cluster near them.
Polarization of Light — Types, Methods & Applications
Polarization of light explains the direction of a light wave's electric field. Learn the main types, one worked example, and common uses.
Projectile Motion — Equations, Range & Examples
Learn what projectile motion is, the core equations, when the range formula works, and one clear worked example.
Quantum Mechanics — Wave-Particle Duality & Schrödinger Equation
Quantum mechanics basics explained through wave-particle duality, the Schrödinger equation, and one clear particle-in-a-box example.
Radioactivity — Alpha, Beta, Gamma & Half-Life
Understand radioactivity fast: what alpha, beta, and gamma radiation are, how half-life works, one clear decay example, and common mistakes to avoid.
Rankine Cycle
Rankine cycle explained: what it is, how the four stages work, how to calculate efficiency, and one simple steam-cycle example.
RC Circuit — Time Constant
Learn what the RC time constant means, how tau = RC predicts charging and discharging speed, and how to solve a simple example.
Reinforced Concrete Design — Basics
Learn what reinforced concrete design means, why steel is placed where the concrete is in tension, and how to read one simple beam example without jumping into code-specific.
Renewable Energy — Types, Pros & Cons
Learn what renewable energy is, the main types, one clear wind-power example, the real pros and cons, and the mistakes students often make.
Retaining Wall Design
Retaining wall design means estimating soil pressure, checking stability, and understanding why drainage can change the answer.
Reynolds Number
Learn what the Reynolds number measures, when $Re = \rho v L / \mu$ applies, and how to interpret one clear pipe-flow example without overgeneralizing.
Rotational Motion — Torque, Angular Momentum & Moment of Inertia
Rotational motion explained clearly: what torque, moment of inertia, and angular momentum mean, how they connect, and one fixed-axis example.
Schrödinger Equation
Learn what the Schrödinger equation means, when the time-independent form applies, and how a particle in a box shows quantized energy.
Second Law of Thermodynamics
A clear explanation of the second law of thermodynamics, entropy, one worked example, and the mistakes students often make.
Semiconductors — P-Type, N-Type & PN Junction
Learn p-type and n-type semiconductors, how doping works, and why a PN junction conducts in forward bias but resists current in reverse bias.
Shear Force and Bending Moment Diagram
Understand shear force and bending moment diagrams fast: what the graphs mean, how to read their shapes, and one simple beam example.
Signal Processing — Fourier Transform, Filters & Sampling
Learn what signal processing is, how Fourier transforms and filters work, and why sampling rate matters.
Simple Harmonic Motion
Understand simple harmonic motion fast with the defining condition, the core formulas, one spring example, and the mistakes that cause the most confusion.
Simple Machines — 6 Types, Mechanical Advantage & Examples
Understand the 6 simple machines, what mechanical advantage means, and how a lever trades force for distance.
Snell's Law — Refraction Formula & Critical Angle
Snell's law explained clearly: the refraction formula, what the angles mean, how critical angle works, and one water-to-air example.
Soil Mechanics — Basics
Soil mechanics explained simply: what effective stress means, why water matters, one worked example, and common mistakes.
Solar Energy — How Solar Panels Work & Efficiency
Understand how solar panels turn sunlight into electricity, what efficiency really means, one clear power example, and the most common mistakes.
Solar System — Planets, Orbits & Key Facts
Learn what the solar system is, the planets in order, how orbits work, and one clear Mars example without textbook overload.
Solid State Physics — Crystal Structure, Band Theory & Lattice
Solid state physics explains how crystal structure and band theory determine whether a material behaves like a metal, semiconductor, or insulator.
Sound Waves — Properties, Speed & Decibels
Understand sound waves, the speed of sound, wavelength, frequency, and what decibels actually measure in one clear explainer.
Space Exploration — Missions, Rockets & Key Milestones
Space exploration explained: how rockets reach orbit, why speed matters, one clear example, major milestones, and common mistakes.
Special Relativity
Special relativity explains why fast motion changes measurements of time, length, and simultaneity, with one clear time-dilation example.
Specific Heat — Formula, Q = mcΔT & Problems
Learn specific heat, when to use Q = mcΔT, and how to solve a simple temperature-change problem without common mistakes.
Specific Heat Capacity
Learn what specific heat capacity means, when the heat equation applies, and how to solve a simple heating example clearly.
Standing Waves
Standing waves explained clearly: what they are, why nodes and antinodes form, when string formulas apply, and one worked example.
Static Electricity — Charging, Coulomb's Law & Examples
Learn what static electricity is, how charging happens, where Coulomb's law fits, and how to solve a simple force example.
Statistical Mechanics — Boltzmann Distribution & Ensembles
Learn statistical mechanics fast: what the Boltzmann distribution means, when each ensemble applies, and one simple worked example.
Stress-Strain Curve
Stress-strain curve explained: learn stress, strain, elastic vs plastic regions, Young's modulus, and one clear worked example.
Structural Analysis — Basics
Learn what structural analysis means, what engineers actually calculate, and how a simple beam example connects loads, reactions, and bending.
Superposition Theorem — Circuits
Understand the superposition theorem in circuits, when it works, how to turn off sources, and one clear worked example.
Surface Tension — Formula, Capillarity & Applications
Surface tension explained with the main formula, capillary rise, droplet vs bubble pressure, one worked example, and common mistakes.
Thermodynamic Cycles — Carnot, Otto, Diesel & Rankine
Learn what a thermodynamic cycle is and how Carnot, Otto, Diesel, and Rankine cycles differ, with one clear worked example.
Thevenin's Theorem
Thevenin's theorem explained clearly: what it means, when it works, how to find the equivalent circuit, and one solved example.
Three-Phase Power
Understand three-phase power, why the phases are 120 degrees apart, the main balanced-system formula, and one clear example.
Torque — Formula and Examples
Learn what torque means, how the formula $\tau = rF\sin\theta$ works, when torque is zero, and how to solve a simple door example.
Torsion — Shear Stress in Shafts
Learn what the torsion formula means, when $\\tau = Tr/J$ applies, and how to compute shear stress in a circular shaft from one clear example.
Transfer Function
Understand what a transfer function means, when H(s) = Y(s)/X(s) applies, and how an RC low-pass example works.
Transistors — BJT and MOSFET
Understand what a transistor does, how BJTs and MOSFETs differ, and when each one makes more sense in a simple circuit.
Truss Analysis — Method of Joints
Understand truss analysis with the method of joints: what it assumes, how to solve a simple truss, and how to read tension vs. compression.
Vector Addition
Learn what vector addition means in physics, how to add vectors with components, and how to find the resultant with one clear example.
Viscosity — Definition, Formula, and Example
Learn what viscosity means, when $\\tau = \\mu \\frac{du}{dy}$ applies, and how to solve one clear shear-stress example.
Wave Equation
Understand the wave equation fast with the 1D form, plain-language intuition, one worked sine-wave example, and common mistakes.
Wave Optics — Diffraction, Interference & Polarization
Wave optics explains interference, diffraction, and polarization in plain language, with one clear example and the mistakes students make most.
Wave Properties — Wavelength, Frequency, Amplitude & Speed
Learn what wavelength, frequency, amplitude, and wave speed mean, how they fit together, and how to use one clear example without mixing them up.
What Is Conservation of Energy? Meaning and Example
Conservation of energy explained clearly: what it means, when total energy stays constant, and one falling-object example.
Work Energy Theorem
Learn the work-energy theorem, what $W_{net} = \Delta K$ means, when to use it, and how to solve a clear stopping-distance example.
Work Function — Photoelectric Effect & Threshold Frequency
Learn what the work function is, how it sets threshold frequency, and how to use it in a clear photoelectric-effect example.
Work, Energy and Power — Formulas & Examples
Learn what work, energy, and power mean in physics, when the main formulas apply, and how one lifting example connects all three.
Young's Modulus — Stress, Strain & Elasticity
Understand Young's modulus, the stress-strain ratio for elastic deformation, with one clear rod-stretch example.