4.1 Introduction to Engines

• The meaning of an engine (a machine that converts energy into motion)
• How an engine converts fuel energy into mechanical energy
• The uses of engines in day-to-day life

• define an engine as used in power mechanics
• explain how an engine converts energy into motion
• identify the uses of engines in day-to-day life
• appreciate the importance of engines

“How does an engine convert energy into motion?”

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1. What an engine is
   40 min · 1 practice tasks · quiz
   The definition of an engine as a machine that converts energy into motion, what goes in and what comes out.
2. The energy chain
   40 min · 1 practice tasks · quiz
   How chemical energy in fuel becomes heat and then mechanical energy, and why energy is never created or destroyed.
3. Burning fuel releases heat
   40 min · 1 practice tasks · quiz
   How combustion combines fuel with air, what it produces, and why the fuel-air ratio matters.
4. Expanding gas pushes the piston
   40 min · 1 practice tasks · quiz
   How the heat of combustion becomes a push on the piston, and why the cylinder is shaped as it is.
5. From push to rotation
   40 min · 1 practice tasks · quiz
   How the connecting rod and crankshaft turn the straight-line movement of the piston into the rotation a vehicle needs.
6. Where the fuel energy goes
   40 min · 1 practice tasks · quiz
   The rough split of fuel energy into useful work, cooling, exhaust and friction, and why the cooling system is essential.
7. Engines in transport
   40 min · 1 practice tasks · quiz
   How engine size follows from the work a vehicle must do, from a boda boda to a lorry.
8. Engines in farming and industry
   40 min · 1 practice tasks · quiz
   Tractors, mills, saws and pumps, and why an engine rather than an electric motor is the practical answer away from the grid.
9. Engines making electricity and moving water
   40 min · 1 practice tasks · quiz
   How an engine coupled to an alternator makes electricity and coupled to a pump moves water, and why the engine does not care what it drives.
10. Engines today and tomorrow
    40 min · 1 practice tasks · quiz
    Why engines still dominate, what hybrids and battery vehicles change, and what it means for a mechanic starting now.