Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Thermal Radiation: Power Balance in Illuminated Rectangular Prism

Description

This lecture covers the correction of question 7 from a multiple-choice test, focusing on finding the temperature of an illuminated rectangular prism using formulas for intensity and power. The power balance is analyzed for the prism, considering the power received and emitted from its surfaces.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Related concepts (18)

Surface area

The surface area (symbol A) of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc length of one-dimensional curves, or of the surface area for polyhedra (i.e., objects with flat polygonal faces), for which the surface area is the sum of the areas of its faces. Smooth surfaces, such as a sphere, are assigned surface area using their representation as parametric surfaces.

Black-body radiation

Black-body radiation is the thermal electromagnetic radiation within, or surrounding, a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific, continuous spectrum of wavelengths, inversely related to intensity, that depend only on the body's temperature, which is assumed, for the sake of calculations and theory, to be uniform and constant.

Kirchhoff's law of thermal radiation

In heat transfer, Kirchhoff's law of thermal radiation refers to wavelength-specific radiative emission and absorption by a material body in thermodynamic equilibrium, including radiative exchange equilibrium. It is a special case of Onsager reciprocal relations as a consequence of the time reversibility of microscopic dynamics, also known as microscopic reversibility. A body at temperature T radiates electromagnetic energy.

Non-ionizing radiation

Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule. Instead of producing charged ions when passing through matter, non-ionizing electromagnetic radiation has sufficient energy only for excitation (the movement of an electron to a higher energy state). Non-ionizing radiation is not a significant health risk.

Area

Area is the measure of a region's size on a surface. The area of a plane region or plane area refers to the area of a shape or planar lamina, while surface area refers to the area of an open surface or the boundary of a three-dimensional object. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat.

Related lectures (32)

Radiative Properties of Surfaces: Heat Transfer Fundamentals

Explains the fundamental concepts of radiative heat transfer and surface properties essential for energy analysis.

Advanced Heat Transfer: Fundamentals and Applications

Covers the fundamentals of advanced heat transfer, focusing on radiative heat transfer principles and their applications in energy systems.

Monte Carlo Methods in Thermal Radiation: Applications and Solutions

Discusses the application of Monte Carlo methods to thermal radiation and energy transfer in participating media.

Radiative Exchange in Heat Transfer: View Factors and Properties

Discusses radiative exchange principles, focusing on view factors and their applications in heat transfer calculations.

Thermal radiation and Einstein coefficients