Thermal Phenomena

Understanding everyday thermal phenomena and heat-related effects

Topics

How does a refrigerator work?

A refrigerator works by using a refrigerant that evaporates inside (absorbing heat and cooling) and condenses outside (releasing heat). A compressor circulates the refrigerant, and the cycle continuously removes heat from inside the refrigerator, keeping it cold.

How does a thermometer work?

A thermometer works by using a substance that expands or contracts with temperature changes. Liquid thermometers use mercury or alcohol that expands in a narrow tube, with the height indicating temperature. Digital thermometers use temperature-sensitive electrical properties.

Why do we feel cold when wet?

We feel cold when wet because water evaporates from our skin, and evaporation requires energy (latent heat of vaporization). This energy comes from our body heat, cooling our skin and making us feel cold.

Why does metal expand when heated?

Metal expands when heated because increased temperature makes atoms vibrate more, increasing the average distance between atoms. This thermal expansion occurs in all materials but is more noticeable in metals due to their rigid structure and common use in construction.

Why does wind feel cold?

Wind feels cold because it increases heat loss from your body through convection and evaporation. Moving air removes the warm air layer around your skin and increases evaporation of moisture, both of which cool your body faster than still air.