Which describes a source of radiation heat?
A. Liquid or gas circulating to move the heat
B. The sun sending out electromagnetic waves
C. Two molecules colliding with each other
D. Objects having kinetic energy because of their motion
The correct answer is B. The sun sending out electromagnetic waves.
To get this answer, let's break down each option:
A. Liquid or gas circulating to move the heat: This describes convection heat transfer, which involves the movement of a heated fluid. It does not specifically refer to radiation heat.
C. Two molecules colliding with each other: This refers to conduction heat transfer, which occurs when heat is transferred directly through molecular collision. It does not specifically refer to radiation heat.
D. Objects having kinetic energy because of their motion: This describes thermal energy, which is associated with the motion of particles. However, it does not specifically refer to radiation heat.
B. The sun sending out electromagnetic waves: This correctly describes radiation heat transfer. The sun emits energy in the form of electromagnetic waves, including visible light, infrared radiation, and ultraviolet radiation. These waves travel through space and transfer heat energy when they are absorbed by objects.
Therefore, option B is the correct answer as it specifically describes a source of radiation heat.