Assertion: Air blown onto the palm through pursed lips feels cold, while air blown with the mouth wide open feels warm.
Reason: Rapid expansion through a narrow opening is nearly adiabatic and cools the air.

Question

Assertion: Air blown onto the palm through pursed lips feels cold, while air blown with the mouth wide open feels warm.

Reason: Rapid expansion through a narrow opening is nearly adiabatic and cools the air.

TestHub · Accepted Answer

Air blown through pursed lips expands rapidly through a small opening, almost adiabatically, so it cools. Air blown with the mouth wide open leaves at body temperature without a sudden expansion. A.

Physics - Heat & Thermo Question with Solution | TestHub

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