Science · Beginner

Physics

Mechanics first, because everything else is built on it — then the rest of an introductory physics course.

Lessons
52 lessons
Total runtime
15 hours of video
Modules
12 modules
Optional lessons
45 optional
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About this course

Classical mechanics is the part of physics that describes the world you can see. Things falling, things colliding, things spinning, things staying still because the forces on them cancel. It was essentially finished by 1700, it is wrong at very high speeds and very small scales, and it remains the correct tool for almost every engineering problem anyone actually faces.

This course is Crash Course Physics through the mechanics sequence, in order. Each episode is about ten minutes and each genuinely depends on the one before it — Newton's laws are meaningless without a clear idea of acceleration, and energy is hard to motivate without force. Watching these out of order is most of why people find physics arbitrary.

The conceptual hurdle is early and specific: Newton's first law. Everyone can recite it and most people's intuition still says that motion needs a continuous push, because on Earth friction makes that appear true. Getting genuinely comfortable with the idea that constant motion is the default state — that it needs no explanation, and only changes do — is the single unlock for the rest of the subject.

A note on scope: the series uses calculus and this course does not teach it. The Calculus course here covers what you need, and taking it first or alongside makes several episodes considerably less mysterious. About ninety minutes of required video, all of it mechanics. Everything after that is optional and covers the rest of an introductory physics course in the same ten-minute format — waves and sound, heat, electricity, magnetism, optics, relativity and quantum mechanics — followed by a handful of full university lectures for the topics that deserve an hour rather than ten minutes. Around fifteen hours in total, and worth far more time than that spent working problems from any textbook.

What you'll be able to do

  • Describe motion precisely: position, velocity and acceleration, and how they relate
  • Apply Newton's three laws to work out what a system will do
  • Account for friction rather than treating it as an inconvenience
  • Explain circular motion and gravity as the same kind of problem
  • Use conservation of energy and momentum to solve problems that would be painful with forces alone

Curriculum

52 lessons · 15 hours

Describing Motion

4 lessons · 40m

  1. 01CompletedMotion in a Straight LineCrashCourseVideoPosition, velocity and acceleration made precise. Everything afterwards is these three quantities in more complicated arrangements, so it is worth being genuinely comfortable before moving on.10m
  2. 02CompletedVectors and 2D MotionOptionalCrashCourseVideoMotion in two dimensions, which is every real trajectory. Skipped in the required path only because the one-dimensional case is enough to get to Newton's laws — take it before anything involving projectiles.10m
  3. 03CompletedDerivativesOptionalCrashCourseVideoThe series uses calculus from here on. Ten minutes on what a derivative is doing physically — velocity as the rate of change of position — rather than how to compute one.10m
  4. 04CompletedIntegralsOptionalCrashCourseVideoThe other half of the same idea, and the reason area under a velocity graph is distance. Pairs with the Calculus course if you want it properly.10m

Forces

2 lessons · 21m

  1. 05CompletedNewton's LawsCrashCourseVideoThe centre of the whole course. The first law is the one to sit with — everyday intuition insists that motion needs a continuous push, and unlearning that is what makes the rest of physics coherent.11m
  2. 06CompletedFrictionCrashCourseVideoThe force that makes the previous lesson counterintuitive. Treating friction as a force like any other, rather than as an annoyance, is what reconciles the theory with what you observe.10m

Circles and Gravity

2 lessons · 19m

  1. 07CompletedUniform Circular MotionCrashCourseVideoWhy something moving in a circle at constant speed is accelerating. A genuinely surprising result the first time, and it follows directly from the definition in the first lesson.9m
  2. 08CompletedNewtonian GravityCrashCourseVideoThe same mathematics applied to orbits. The insight that a falling apple and an orbiting moon are the same phenomenon is arguably the most important single idea in the history of science.10m

Energy and Momentum

5 lessons · 47m

  1. 09CompletedWork, Energy, and PowerCrashCourseVideoA second way to analyse a system, and often a far easier one. Many problems that are grim with forces become almost trivial once framed as energy.10m
  2. 10CompletedCollisionsCrashCourseVideoMomentum conservation, and the distinction between elastic and inelastic collisions. The clearest demonstration of why conservation laws are worth having.10m
  3. 11CompletedRotational MotionOptionalCrashCourseVideoEverything above, restated for things that spin. Optional in the sense that the ideas are structurally identical to what you already know — but the parallel is satisfying and worth seeing drawn.10m
  4. 12CompletedTorqueOptionalCrashCourseVideoRotational force. Follows directly from the rotational motion episode above, and is what you actually need for anything involving a lever, a wheel or a spanner.8m
  5. 13CompletedStaticsOptionalCrashCourseVideoThings that are not moving, and why that is a harder question than it sounds. This is the episode most directly useful if you build anything physical.9m

Fluids and Oscillation

3 lessons · 29m

  1. 14CompletedFluids at RestOptionalCrashCourseVideoPressure and buoyancy — why things float, stated properly rather than as a rule about density.10m
  2. 15CompletedFluids in MotionOptionalCrashCourseVideoFlow, continuity and Bernoulli. The episode that explains aeroplane wings, and corrects the popular explanation of them.10m
  3. 16CompletedSimple Harmonic MotionOptionalCrashCourseVideoA pendulum, a spring, and the same equation underneath both. This is the bridge from mechanics to waves, so take it before the next module.9m

Waves and Sound

3 lessons · 29m

  1. 17CompletedTravelling WavesOptionalCrashCourseVideoWavelength, frequency and speed, and the fact that a wave moves energy without moving matter. Everything about light later depends on this episode.8m
  2. 18CompletedSoundOptionalCrashCourseVideoWaves you can hear, including the Doppler effect and why an ambulance changes pitch as it passes.10m
  3. 19CompletedThe Physics of MusicOptionalCrashCourseVideoStanding waves, harmonics and why two instruments playing the same note sound different. The most enjoyable episode in the series.11m

Heat and Thermodynamics

5 lessons · 47m

  1. 20CompletedTemperatureOptionalCrashCourseVideoWhat temperature actually measures, which is not the same thing as heat. Getting that distinction clear early prevents most later confusion.9m
  2. 21CompletedKinetic Theory and Phase ChangesOptionalCrashCourseVideoHeat as the motion of particles, which is the point at which thermodynamics stops being a set of rules and becomes mechanics applied to very many things at once.9m
  3. 22CompletedThe Physics of HeatOptionalCrashCourseVideoConduction, convection and radiation — how energy actually moves from one thing to another.9m
  4. 23CompletedThermodynamicsOptionalCrashCourseVideoThe laws, including entropy. Ten minutes on the one part of physics that says something about the direction of time.10m
  5. 24CompletedEnginesOptionalCrashCourseVideoThermodynamics applied, and the reason no engine can be perfectly efficient. A good demonstration that the second law is a practical constraint rather than an abstraction.10m

Electricity

7 lessons · 1h 11m

  1. 25CompletedElectric ChargeOptionalCrashCourseVideoWhere the second half of introductory physics begins. Charge behaves a great deal like mass in Newtonian gravity, which makes this module easier than it looks if you have done the mechanics.10m
  2. 26CompletedElectric FieldsOptionalCrashCourseVideoThe field idea, which is the most important conceptual step in this half of the course — force at a distance replaced by something present everywhere.10m
  3. 27CompletedVoltage, Electric Energy and CapacitorsOptionalCrashCourseVideoVoltage as potential energy per charge. Once that lands, most circuit intuition follows without memorisation.10m
  4. 28CompletedElectric CurrentOptionalCrashCourseVideoCharge in motion, and the point where this stops being theory and starts describing the wiring in your walls.8m
  5. 29CompletedDC Resistors and BatteriesOptionalCrashCourseVideoOhm's law and simple circuits. Enough to understand a breadboard, which makes this the most immediately practical episode here.11m
  6. 30CompletedCircuit AnalysisOptionalCrashCourseVideoSeries and parallel, and how to reduce a messy circuit to a simple one.11m
  7. 31CompletedCapacitors and KirchhoffOptionalCrashCourseVideoThe rules that let you solve a circuit no amount of rearranging will simplify. The most technical episode in the electricity module.11m

Magnetism

6 lessons · 59m

  1. 32CompletedMagnetismOptionalCrashCourseVideoMagnetic fields, and the fact that they are produced by moving charge rather than being a separate phenomenon.10m
  2. 33CompletedAmpère's LawOptionalCrashCourseVideoThe relationship between a current and the field around it, stated precisely.9m
  3. 34CompletedInductionOptionalCrashCourseVideoA changing magnetic field produces a current. This one sentence is most of the electrical grid, and this is the episode that explains it.10m
  4. 35CompletedHow Power Gets to Your HomeOptionalCrashCourseVideoInduction applied at national scale — transformers, transmission voltages and why the grid is built the way it is.9m
  5. 36CompletedAC CircuitsOptionalCrashCourseVideoAlternating current, which is what actually comes out of a socket, and the reason it won the format war.10m
  6. 37CompletedMaxwell's EquationsOptionalCrashCourseVideoFour equations that unify everything in the last two modules and predict light as a consequence. Arguably the high point of classical physics.11m

Light and Optics

4 lessons · 39m

  1. 38CompletedGeometric OpticsOptionalCrashCourseVideoLight as rays — reflection, refraction, lenses and mirrors. Enough to explain glasses, cameras and why a straw looks bent in water.10m
  2. 39CompletedLight Is WavesOptionalCrashCourseVideoWhere the ray picture breaks down and the wave picture takes over. The double-slit experiment appears here, and it matters again in the next module.10m
  3. 40CompletedSpectra and InterferenceOptionalCrashCourseVideoInterference patterns and diffraction gratings — how we know what distant stars are made of.8m
  4. 41CompletedOptical InstrumentsOptionalCrashCourseVideoTelescopes, microscopes and the eye. Optics applied, and a good place to stop if you only wanted the practical half.11m

Modern Physics

5 lessons · 46m

  1. 42CompletedSpecial RelativityOptionalCrashCourseVideoWhere the mechanics you learned in module one turns out to be an approximation. Nine minutes, and genuinely unsettling if you take it seriously.9m
  2. 43CompletedQuantum Mechanics — Part 1OptionalCrashCourseVideoThe experiments that forced the theory, rather than the theory presented as strange facts. That ordering is what makes it comprehensible.9m
  3. 44CompletedQuantum Mechanics — Part 2OptionalCrashCourseVideoWave functions, uncertainty and what the theory actually claims. Ten minutes is not enough for this, which is why the Yale and MIT lectures below are here.9m
  4. 45CompletedNuclear PhysicsOptionalCrashCourseVideoRadioactivity, fission and fusion — quantum mechanics with consequences you can point at.10m
  5. 46CompletedAstrophysics and CosmologyOptionalCrashCourseVideoThe last episode, applying everything above at the largest possible scale. A satisfying place to finish the series.9m

Longer Lectures

6 lessons · 7h 52m

  1. 47CompletedAn Entire Physics Class in 76 MinutesOptionaltmodxVideoA single-sitting summary of the whole subject, unusually well animated. Good as revision after the series, or as a preview before it.1h 16m
  2. 48CompletedThermodynamics — Yale Lecture 21OptionalYaleCoursesVideoA real university lecture at real university pace, with the derivations the ten-minute episode has to skip. Ramamurti Shankar is one of the great physics lecturers.1h 11m
  3. 49CompletedQuantum Mechanics I — Yale Lecture 19OptionalYaleCoursesVideoThe key experiments and wave-particle duality, done properly. This is the hour that makes the Crash Course quantum episodes stop feeling like a list of surprising claims.1h 14m
  4. 50CompletedIntroduction to Superposition — MIT 8.04OptionalMIT OpenCourseWareVideoMIT's opening quantum lecture, built around an experiment performed live. The most rigorous item on this page and worth the effort.1h 16m
  5. 51CompletedSpecial Relativity — Stanford Lecture 1OptionalStanfordVideoLeonard Susskind teaching relativity to adults who are not physics majors. Two hours, mathematical but patient, and the natural follow-up to the nine-minute episode.1h 58m
  6. 52CompletedPhysics 2 — Basic IntroductionOptionalThe Organic Chemistry TutorVideoAn hour of worked problems across electricity and magnetism. The Crash Course episodes explain; this is where you find out whether you can actually use them.57m

Credits

Every lesson in this course was made by one of these channels. Tubeversity sequenced them; it did not make them. If a course is useful to you, the people below are the ones who earned it.