B.1 Flashcards 3

Front

Definition of a black body

Back

A theoretical object that absorbs all energy from all wavelengths of light from the electromagnetic spectrum.

Front

Black body radiation

Back

Emits radiation containing all wavelengths of light from the electromagnetic spectrum.

Front

Existence of black bodies

Back

Black bodies do not exist in real life, but some objects like stars are close approximations.

Front

Emission spectra

Back

Graphs that illustrate the intensities of radiation emitted by black bodies at different wavelengths.

Front

Wien’s Law

Back

States that the absolute temperature of a star is inversely proportional to the wavelength of maximum radiation intensity.

Front

Luminosity of a black body

Back

The amount of energy it emits per second, measured in watts (W).

Front

Factors affecting luminosity

Back

Directly proportional to the surface area of the star and the absolute temperature raised to the fourth power.

Front

Apparent brightness of a star

Back

How bright a star appears to an observer, measured in watts per square meter (W m⁻²).

Front

Factors affecting apparent brightness

Back

Directly proportional to the star’s luminosity and inversely proportional to the square of the distance to the observer.

Front

Black body in thermal equilibrium

Back

Emits black body radiation containing all wavelengths of light.