. An aircraft air-cooled piston engine is a good example of convection being used to transfer heat. An aircraft air-cooled piston the engine is a good example of convection being used to transfer heat

coal is not sustainable because it will one day run out.

not sure if this what   you'r looking for would be percent composition

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.