Radiant energy

Definition

Radiant energy is the energy of electromagnetic waves. It can be emitted or absorbed by objects and is a key factor in various physical processes.

5 Must Know Facts For Your Next Test

1. Radiant energy includes visible light, infrared radiation, ultraviolet radiation, X-rays, and radio waves.
2. The amount of radiant energy emitted by an object depends on its temperature, described by Planck's law.
3. Radiant energy plays a crucial role in the conservation of energy principle since it can transform into other forms such as thermal or electrical energy.
4. The Stefan-Boltzmann law states that the total radiant heat power emitted from a surface is proportional to the fourth power of its absolute temperature: $P = \sigma A T^4$.
5. Photosynthesis in plants converts solar radiant energy into chemical energy.

Review Questions

• What types of electromagnetic waves are considered part of radiant energy?
• How does the Stefan-Boltzmann law relate to radiant energy emission?
• In what ways can radiant energy be transformed into other forms of energy?

Related terms

Electromagnetic Spectrum: The range of all types of electromagnetic radiation, including gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves.

Stefan-Boltzmann Law: A principle that states the power radiated per unit area of a black body is proportional to the fourth power of its absolute temperature: $P = \sigma A T^4$.

Planck's Law: Describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature as a function of wavelength or frequency.