Alternatively, why does the force created by blowing out air feel so much stronger than the force created by sucking in air?
Ok, so forget the human factor involved in blowing out candles. Consider a vacuum cleaner with a suction end and a blower end. Anyone who has tried it out notices the blower end creates a much stronger force than the suction end, despite the discharge being (more or less) equal at both ends.
Why does this happen?
Answer
In a blower, the air is directed along the axis of the blower as it exits, creating a high-pressure narrow cone. Exit pressure can also be multiple times of atmospheric pressure.
At a sucker entry, the low-pressure zone is fed by a much wider angle of atmospheric air at atmospheric pressure. Additionally, the underpressure can at most be 1x atmospheric pressure. therefore the inflow has an upper limit to its velocity.
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