All Flashcards
Define blackbody radiation.
Electromagnetic energy emitted by an object due to its temperature.
What is a blackbody?
An idealized object that absorbs all incoming radiation and emits energy based solely on its temperature.
Define Wien's displacement constant.
The constant (b ≈ 2.898 x 10⁻³ m⋅K) that relates the peak wavelength of emitted radiation to the temperature of a blackbody.
What is the Stefan-Boltzmann constant?
The constant (σ ≈ 5.67 x 10⁻⁸ W m⁻² K⁻⁴) that relates the total power emitted by a blackbody to its surface area and temperature.
Define Planck's constant.
The constant (h) that relates the energy of a photon to its frequency (E = hf).
What is 'ultraviolet catastrophe'?
The prediction by classical physics that a blackbody would emit infinite energy at short wavelengths.
What is the effect of increasing the temperature of a blackbody on its emitted radiation?
As temperature increases, the peak wavelength shifts to shorter wavelengths (blue shift), and the total power emitted increases significantly.
What is the effect of increasing the surface area of a blackbody on its power emission?
Increasing the surface area of a blackbody directly increases the total power emitted, as described by the Stefan-Boltzmann Law (P = AσT⁴).
Compare and contrast classical physics and Planck's quantum approach in explaining blackbody radiation.
Classical physics failed to explain the blackbody spectrum, leading to the ultraviolet catastrophe. Planck's quantum approach introduced quantized energy, resolving the issue.