Final answer:
Vehicles such as buses use separate air tanks mainly for air brake systems, and advancements in vehicle technology like fuel cells and hybrid systems are reducing emissions for cleaner air.
Explanation:
Some vehicles such as buses have a separate air tank which can be used to release air during various applications, including the operation of air brakes or the inflation of airbags in the event of a collision. In the context of buses and heavy vehicles, this air is typically used to operate the pneumatic brake system, which requires a large volume of compressed air to function effectively.
Fuel cell technology is another innovative solution being implemented to reduce emissions in public transportation. These fuel cells generate electricity through the catalytic combination of elemental hydrogen and oxygen, with only water as a by-product, contributing to cleaner air and better health.
Vehicles contribute to air pollution by emitting nitrogen oxides, carbon monoxide, and volatile hydrocarbons, which can form smog. Technological advancements like the catalytic converter and the development of hybrid and electric vehicles aim to reduce these emissions.
Hybrid vehicles, for instance, combine a combustion engine with an electric motor, allowing the engine to run at a more consistent speed for enhanced fuel economy and lower emissions. Electric vehicles, while they present challenges like limited range and longer charging times, do not emit pollutants while driving.