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Crank a cutaway four-stroke by hand, shift through the gears, crash-test a crumple zone and compare where the energy goes in a petrol car and an EV.

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The course

7 worlds · 24 lessons

World 1 · Four Strokes, One Bang

FREEHow a piston engine turns burning fuel into rotation
  1. 01Inside the cylinderPiston, connecting rod and crankshaft · 12 min
  2. 02Four strokes: intake, compression, power, exhaustThe cycle that repeats every two turns · 13 min
  3. 03Valve timing and ignitionOpening early, firing early · 13 min
  4. 04Many cylinders, one smooth rideFiring order and balance · 12 min

World 2 · Diesel, Rotary and Electric

PROThree different ways to turn energy into motion
  1. 01Petrol vs dieselSpark or squeeze · 13 minPRO
  2. 02The WankelA triangle that spins · 12 minPRO
  3. 03The electric motorTorque from zero rpm · 13 minPRO
  4. 04The battery bayEnergy you carry · 13 minPRO

World 3 · Gears: Torque vs Speed

PROWhy a car needs a gearbox, and what power really is
  1. 01Power is torque times speedThe relation behind every engine curve · 12 minPRO
  2. 02Gear ratiosTrading speed for force · 13 minPRO
  3. 03Shifting and efficiencyThe right gear for the road · 12 minPRO

World 4 · Brakes and Regenerative Braking

PROHow far a car needs to stop, and where the energy goes
  1. 01Stopping distanceThinking plus braking · 13 minPRO
  2. 02How friction brakes workHydraulics and heat · 13 minPRO
  3. 03Regenerative brakingTurning the brakes into a generator · 13 minPRO

World 5 · Crumple Zones and Airbags

PROForce, time and the engineering of surviving a collision
  1. 01Force, time and impulseThe physics of a crash · 13 minPRO
  2. 02Crumple zonesDesigned to fold · 13 minPRO
  3. 03Seat belts and airbagsSpreading the force · 13 minPRO
  4. 04Test, measure, redesignThe engineering loop · 12 minPRO

World 6 · Cutting Through the Air

PROWhy speed costs so much energy
  1. 01Drag grows with speed squaredThe force that dominates at speed · 13 minPRO
  2. 02Shape mattersFrom boxes to teardrops · 12 minPRO
  3. 03Drag, rolling resistance and your fuel billTwo resistances, one trade-off · 13 minPRO

World 7 · EV vs Petrol: Where the Energy Goes

PROFollowing the energy from source to wheels
  1. 01Follow the energy: a petrol carReading a Sankey diagram · 13 minPRO
  2. 02Follow the energy: an electric carThe chain from the wall socket to the wheels · 13 minPRO
  3. 03Where does the electricity come from?The whole picture · 14 minPRO