Which scenario demonstrates radiation as a mechanism of heat transfer?

Which scenario demonstrates radiation as a mechanism of heat transfer?

• A. A pot on a stove becoming hot due to direct contact with the burner.
• B. Warm air rising in a room from a heater.
• C. Water boiling due to being heated by a stove.
• D. The Sun warming the Earth through space.

Answer: (D)

Radiation transfers heat through electromagnetic waves and does not require a medium to travel. The Sun warming the Earth through space demonstrates this because sunlight (and other radiant energy) travels through the vacuum of space and heats the planet when it reaches Earth. The other scenarios rely on contact or moving air: a pot heating from direct contact transfers energy by conduction at the interface; warm air rising from a heater shows convection as heated air moves and carries heat; water boiling from a stove mainly involves conduction of heat from the pot into the water. So the Sun warming the Earth through space is the example that shows heat transfer by radiation.

Radiation transfers heat through electromagnetic waves and does not require a medium to travel. The Sun warming the Earth through space demonstrates this because sunlight (and other radiant energy) travels through the vacuum of space and heats the planet when it reaches Earth. The other scenarios rely on contact or moving air: a pot heating from direct contact transfers energy by conduction at the interface; warm air rising from a heater shows convection as heated air moves and carries heat; water boiling from a stove mainly involves conduction of heat from the pot into the water. So the Sun warming the Earth through space is the example that shows heat transfer by radiation.