GED Science TestPhysical ScienceMedium
A student observes a campfire. They notice that they can feel the heat from the fire even when standing several feet away, without touching the flames or the hot air rising directly above it. What primary method of heat transfer is responsible for the heat felt by the student?
- AAbsorption
- BRadiation
- CConduction
- DConvection
Show answer & explanationAnswer & explanation
Correct answer: B. Radiation
Radiation is the transfer of heat through electromagnetic waves (like infrared radiation) and does not require a medium. The student feels the heat without directly touching the fire (conduction) or being in the path of the rising hot air (convection), indicating radiation is the primary mechanism.
Why the other options are wrong
- A. Absorption is a process where energy is taken in, not a primary method of heat transfer between objects.
- C. Conduction requires direct contact between objects.
- D. Convection involves heat transfer through the movement of fluids (liquids or gases), usually hot air rising.
Heat Transfer: Radiation
Radiation is the transfer of heat energy in the form of electromagnetic waves (e.g., infrared, visible light). It does not require a medium and can travel through a vacuum.
- Transfers heat via electromagnetic waves
- Does not require a medium (can travel through vacuum)
- Example: heat from the sun, heat from a fire
Memory trick: CCC-R (Conduction, Convection, Radiation)