absorptivity
/,æbsɔ:p'tiviti/
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Definition
- Noun:
- (Physics): The property of a body that determines the fraction of the incident radiation or sound flux that is absorbed by the body. It is a measure of how much energy a material absorbs compared to what it receives.
Usage Examples
- Noun:
- The absorptivity of the black paint is very high, making it ideal for solar collectors.
- Scientists measured the material's absorptivity across different wavelengths of light.
Advanced Usage
- "Spectral absorptivity": Refers to absorptivity measured at a specific wavelength or across a range of wavelengths.
- The spectral absorptivity of the glass changes in the infrared range.
- "Thermal absorptivity": Often used in the context of a material's ability to absorb heat radiation.
- The thermal absorptivity of the ceramic coating improves the oven's efficiency.
Variants and Related Words
- Absorbance (n): In analytical chemistry, a logarithmic measure of the amount of light absorbed by a substance. Related to but distinct from absorptivity.
- Absorption coefficient (n): A measure of how easily a material absorbs radiation per unit distance; closely related to absorptivity.
- Absorptive (adj): Having the ability or tendency to absorb.
- The absorptive qualities of the sponge are excellent.
Synonyms
- Absorption factor: A term sometimes used interchangeably with absorptivity.
- Absorptive power: An older or more general term for the capacity to absorb.
Notes on Meaning
- Physics vs. General Use: In physics and engineering, "absorptivity" is a precise, quantitative property. In more general contexts, it is rarely used; the simpler noun "absorption" is preferred.
- Relation to Emissivity: In thermodynamics, for a body in thermal equilibrium, its absorptivity at a given wavelength equals its emissivity at that same wavelength (Kirchhoff's law of thermal radiation).
Noun
- (physics) the property of a body that determines the fraction of the incident radiation or sound flux absorbed or absorbable by the body