There are at least 2 different contexts where we use the word "burn" on the phase 2 cp course.

When used in the context of engines and combustion, we speak of how we burn fuel. Fuels used in plant machinery contain engrgy. In order to release that energy so that we can do some work with it, we burn the fuel. As the fuel burns, its energy is converted from chemical energy to heat energy.
Heat energy acts on the crown of the piston, forcing it down the cylinder and turning the crankshaft.
This converts the heat energy into mechanical energy. We transmit this energy through the gearbox and drive shaft to the road wheels or tracks, thus moving the vehicle. The burning process is initiated in two main ways in engines: In a petrol engine, a spark plug is used, and in a diesel engine, air is compressed so much that it becomes very hot. Into this hot air, we inject atomised fuel, which after a short delay period, begins to burn, thus releasing its energy.

When used in the context of computers, to "burn" a CD-R (Compact Disc-Recordable) is to write information to the disc by means of a low-intensity laser, which "burns" the digital information onto the disc.

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