Q40.3-1CC. - Campbell Biology

Question

What mode of heat exchange is involved in “wind chill,” when moving air feels colder than still air at the same temperature? Explain.

 

Step-by-Step Solution

Answer

Convection is the mode of transfer of heat during wind-chill; this results in heat loss when moving air brushes against the skin surface.

Step 1:Heat transfer

The physical process in which heat transfer occurs between material bodies due to temperature differences is called heat transfer. Examples of thermal energy during heat transfer include warmth from the sun and baking in an oven.

Some applications of heat transfer are nature (weather and climate), domestic applications (ovens and stones), and energy production (solar energy conversion).

Step 2: Wind-chill

The term wind-chill refers to a measurement of feels-like temperature that causes rapid heat loss from the living body like humans. When it is windy, cold breeze or lower temperature air passes against the skin. This will result in lowering down the skin temperature.

Step 3: Convection

The moving air absorbs heat from the skin surface, resulting in heat loss due to convection (molecular motion of particles causes heat to transfer through a fluid).

The cool air due to the wind chill will replace the warm air from the exposed skin and drop the skin temperature.