Master Physics Through Interactive Learning
What do you want to learn? Search 120+ concept guides, 50+ step-by-step calculators, interactive simulations and practice problems — free forever.
Popular: AC Basics — Sine Waves, Frequency and RMS Voltage · Acceleration — Definition, Formula and Worked Examples · Aerospace Physics Basics — Lift, Thrust, Drag and Orbits · Angular Momentum Explained — L = Iω and Its Conservation
Explore by subject
Nine branches of physics, each a complete learning hub with guides, formulas, calculators and practice.
🏭 Applied Physics
Physics inside the world you live in.
8 key topics⚡ Electricity & Magnetism
Charges, currents, circuits and magnetism.
6 key topics💧 Fluid Mechanics
Liquids and gases in motion and at rest.
8 key topics📐 Math for Physics
The math toolkit every physics student needs.
8 key topics🚀 Classical Mechanics
How things move — forces, motion, energy and momentum.
7 key topics⚛️ Modern Physics
Relativity, quanta, atoms and nuclei.
7 key topics🔭 Optics
Light, lenses, mirrors and color.
7 key topics🔥 Thermodynamics
Heat, energy and the arrow of time.
7 key topics🌊 Waves & Oscillations
How energy travels — sound, light and vibrations.
Featured concept guides
Deep, intuitive explanations — physical intuition first, mathematics second.
AC Basics — Sine Waves, Frequency and RMS Voltage
Alternating current basics: the sine wave, frequency and period, peak vs RMS voltage (why 120 V mains peaks at 170 V), and how resistors, capacitors and…
High SchoolAcceleration — Definition, Formula and Worked Examples
Acceleration is the rate of change of velocity: a = Δv/Δt. Units, vector direction, sign conventions, and worked examples from cars to free fall.
High SchoolAerospace Physics Basics — Lift, Thrust, Drag and Orbits
Aerospace physics basics: the four forces of flight, how wings really make lift, thrust and drag, orbits and escape velocity.
Introductory CollegeAngular Momentum Explained — L = Iω and Its Conservation
What angular momentum is, why L = Iω is conserved without external torque, and how skaters, divers and satellites exploit it.
High SchoolAtomic Models — From Dalton to Quantum Mechanics
Models of the atom from Dalton to quantum mechanics: Thomson's plum pudding, Rutherford's nucleus, Bohr's orbits (E_n = −13.6 eV/n²), and electron clouds.
High SchoolCar Physics — Braking, Cornering and Crash Safety
Car physics: why braking distance grows with v², cornering and centripetal force, crumple zones, and ABS.
Popular calculators
Every calculator shows the formula, the substitution steps and the final answer — never just a number.
🧮 Acceleration Calculator
Calculate acceleration, final velocity, initial velocity, or time using a = (v − u) / t, with units and steps.…
🧮 Angular Velocity Calculator — ω = Δθ/Δt
How fast something spins: angle swept per unit time.…
🧮 Buoyant Force Calculator — F_b = ρVg
Archimedes' upward force on a submerged object (water: ρ = 1000 kg/m³).…
🧮 Capacitance Calculator — C = Q/V
Capacitance from stored charge and voltage, or solve for Q or V.…
🧮 Carnot Efficiency Calculator — η = 1 − Tc/Th
The maximum possible efficiency of any heat engine.…
🧮 Centripetal Acceleration Calculator — a = v²/r
The inward acceleration that keeps objects moving in circles.…
🧮 Doppler Effect Calculator — f′ = fv/(v − vₛ)
Observed frequency when a sound source moves toward you (v = 343 m/s built in).…
🧮 Electric Field Strength Calculator — E = F/q
Field strength from force on a test charge, or solve for F or q.…
Interactive simulations
Change the variables, watch what happens, build real intuition.
Circuit Lab Simulator
Build real circuits on a virtual breadboard: series, parallel, Ohm's law and Kirchhoff's laws with live meters.
InteractiveCircular Motion Simulator
Spin a mass on a string: change the radius, speed and mass to discover exactly how centripetal force depends on each one.
InteractiveCollision Lab Simulator
Crash two carts head-on: set their masses and velocities, flip between elastic and sticky collisions, and verify momentum conservation.
InteractiveDoppler Effect Simulator
Drive a wave source toward and away from an observer: watch wavefronts bunch up ahead, stretch behind, and shift the heard pitch.
InteractiveFree Fall Simulator
Drop objects from any height in a vacuum. Measure fall time and impact speed — and see why mass does not matter.
InteractiveGas Laws Simulator
Heat a sealed gas, squeeze its piston, or hold a variable constant — and watch pressure, volume and temperature obey the gas laws live.
Learning paths
Guided journeys from zero to mastery — no more random browsing.
AP Physics 1 Prep Path
The full AP Physics 1 syllabus in order: kinematics, dynamics, energy, momentum, rotation, oscillations and fluids.
45 hours · High School (AP)AP Physics 2 Prep Path
The full AP Physics 2 syllabus: fluids, thermodynamics, electricity and magnetism, optics and modern physics.
20 hours · High School to IntermediateElectricity & Magnetism Path
Charge to induction: electric fields, circuits, magnetism and electromagnetic induction in one guided sequence.
10 hours · IntermediateExam Sprint
One week to exam day: rapid review of formulas, high-yield concepts, worked examples and timed practice across all major topics.
15 hours · High School to Introductory CollegeFluids Path: Pressure, Buoyancy and Flow
From still water to Bernoulli's equation: the complete guided path through fluid mechanics.
20 hours · Beginner to IntermediateMath for Physics Path
The mathematical toolkit physics runs on: notation, vectors, trigonometry, graphs and calculus.
25 hours · High School to Introductory CollegeMechanics Mastery
From kinematics to gravitation: the complete guided path through classical mechanics, the foundation of all physics.
15 hours · Intermediate to AdvancedModern Physics Path
Relativity, quanta, atoms and nuclei: the 20th-century revolutions that rewrote physics, in a guided sequence.
40 hours · Beginner to IntermediatePhysics from Zero
Start from absolute zero: measurement, motion, forces, energy, waves, electricity and modern physics — in the order that makes each idea click.
12 hours · High School to Introductory CollegeQuantum First Steps
A gentle first path into quantum physics: the photoelectric effect, duality, atoms, uncertainty and the nucleus.
18 hours · High School to Introductory CollegeThermodynamics Path: Heat, Energy and Entropy
From heat vs temperature to heat engines and entropy: the complete guided path through thermodynamics.
15 hours · High SchoolWaves and Optics Path
From vibrating strings to lenses: waves, sound, and optics in one visual, intuitive path.
Study guides
Exam-focused review for every subject — key formulas, checklists and the mistakes to avoid.
Applied Physics Study Guide
The complete applied physics study guide: machines, energy technology, electronics, engines, fluids engineering, and modern tech — with formulas…
High School · ~15 hoursElectricity and Magnetism Study Guide
The complete electricity and magnetism study guide: charge, fields, circuits, Kirchhoff's laws, power, and induction — with formulas, checklists, and exam…
High School · ~10 hoursFluids Study Guide
The complete fluids study guide: density, pressure, buoyancy, Bernoulli, viscosity, and hydraulics — with formulas, checklists, and exam tactics.
High School · ~10 hoursMath for Physics Study Guide
The complete math-for-physics study guide: vectors, trigonometry, scientific notation, graphing, calculus, and measurement — with formulas, checklists, and…
High School · ~20 hoursMechanics Study Guide
The complete mechanics study guide: kinematics, Newton's laws, friction, energy, momentum, and rotation — with formulas, checklists, and exam tactics.
High School · ~12 hoursModern Physics Study Guide
The complete modern physics study guide: relativity, mass-energy, photons, quantum duality, and nuclear decay — with formulas, checklists, and exam tactics.
High School · ~10 hoursOptics Study Guide
The complete optics study guide: reflection, refraction, lenses, optical instruments, and wave optics — with formulas, checklists, and exam tactics.
High School · ~12 hoursThermodynamics Study Guide
The complete thermodynamics study guide: heat, specific heat, gas laws, the laws of thermodynamics, and heat engines — with formulas, checklists, and exam…
High School · ~12 hoursWaves Study Guide
The complete waves study guide: wave basics, sound, interference, Doppler effect, and oscillations — with formulas, checklists, and exam tactics.
Physics games
Learn by playing — every game ends with a debrief on the physics you just used.
Circuit Puzzle: Pick the Right Resistor
A bulb needs exactly the right current. Choose the resistor that delivers it — Ohm's law is your only tool.
GameTorque Seesaw: Balance the Beam
Place weights on a seesaw to balance it. Every placement is a torque calculation in disguise.
GameCircuits Memory Match
Match 8 circuit terms with their definitions in this memory card game.
GameFluids Memory Match
Match 8 fluid terms with their definitions in this memory card game.
GameHeat Memory Match
Match 8 thermodynamics terms with their definitions in this memory card game.
GameLight Memory Match
Match 8 optics terms with their definitions in this memory card game.
Home experiments
Real physics with household materials — full procedures and explanations.
Bernoulli Ping-Pong Trick
Blow between two hanging ping-pong balls and watch them swing together — then levitate a ball in midair.
ExperimentFoil Boat Buoyancy Challenge
Build aluminum foil boats and load them with pennies — how many can your hull hold before it sinks?
ExperimentChladni Salt Patterns
Sprinkle salt on a vibrating tray and watch it draw the hidden geometry of standing waves.
ExperimentDIY Cloud Chamber
Build a cloud chamber with dry ice and see the vapor trails of real cosmic rays and natural radiation.
ExperimentConvection Currents in Water
Watch hot water rise and cold water sink in a glass — the engine behind weather, oceans, and radiators.
ExperimentSpinning Whistle Doppler Demo
Spin a whistle on a string and hear its pitch rise and fall — the Doppler effect you can feel in your hand.
Learn it. See it. Calculate it. Master it.
Kinexia connects every concept to its formula, calculator, simulation, worked example and practice set.
Start learning →