Opel smoking exhaust Jet engines use a number of rows
Jet engine
Main article: Jet engine
Turbofan Jet Engine
Jet engines use a number of rows of fan blades to compress air which then enters a combustor where it is mixed with fuel (typically JP fuel) and then ignited. The burning of the fuel raises the temperature of the air which is then exhausted out of the engine creating thrust. A modern turbofan engine can operate at as high as 48% efficiency. 24
There are six sections to a Fan Jet engine:
Fan
Compressor
Combustor
Turbine
Mixer
Nozzle
Źródło: https://en.wikipedia.org/wiki/Internal_combustion_engine
Communication between the instructor and the trainee during the course on motorcycle driving license
At least at the beginning of steering a motorcycle can give lessons to the student serving a practical course driving a lot of problems. Of course, as in the case of practical lessons on learning to drive car, also in this case we are dealing with the introduction of the student in handling motorcycle. More problems may occur already during city driving, at a later stage of practical lessons. This is due to the fact that the instructor and student are in different vehicles, usually a motorcyclist driving instructor in the car. Issuing commands and paying attention to mistakes so it can reach out to the student with some delay and it is the source of many problems.
Cars - Costs and benefits
The costs of car usage, which may include the cost of: acquiring the vehicle, repairs and auto maintenance, fuel, depreciation, driving time, parking fees, taxes, and insurance,5 are weighed against the cost of the alternatives, and the value of the benefits ? perceived and real ? of vehicle usage. The benefits may include on-demand transportation, mobility, independence and convenience.7 During the 1920s, cars had another benefit: "couples finally had a way to head off on unchaperoned dates, plus they had a private space to snuggle up close at the end of the night."48
Similarly the costs to society of encompassing car use, which may include those of: maintaining roads, land use, air pollution, road congestion, public health, health care, and of disposing of the vehicle at the end of its life, can be balanced against the value of the benefits to society that car use generates. The societal benefits may include: economy benefits, such as job and wealth creation, of car production and maintenance, transportation provision, society wellbeing derived from leisure and travel opportunities, and revenue generation from the tax opportunities. The ability for humans to move flexibly from place to place has far-reaching implications for the nature of societies.8
Źródło: https://en.wikipedia.org/wiki/Economics_of_car_use