Thermodynamics - Centre for Theoretical Chemistry and Physics
... they are warmed up. But some substances do the opposite by shrinking in certain directions as they are heated and expanding when cooled. Now researchers in the UK have found an inorganic crystalline material composed of silver, cobalt, carbon and nitrogen that expands more than any other known mater ...
... they are warmed up. But some substances do the opposite by shrinking in certain directions as they are heated and expanding when cooled. Now researchers in the UK have found an inorganic crystalline material composed of silver, cobalt, carbon and nitrogen that expands more than any other known mater ...
Temperature
... how hot or cold an objects feels to the touch. Our sense of touch provides us with a qualitative indication of temperature. Our senses are unreliable for this purpose. We need a reliable and reproducible way for establishing the relative “hotness” or “coldness” of objects that is related solely to t ...
... how hot or cold an objects feels to the touch. Our sense of touch provides us with a qualitative indication of temperature. Our senses are unreliable for this purpose. We need a reliable and reproducible way for establishing the relative “hotness” or “coldness” of objects that is related solely to t ...
Classical Physics
... along with the medium. •Fluid near heat source becomes hot, expands, and rises. Surrounding cooler fluid takes its place. Etc. ...
... along with the medium. •Fluid near heat source becomes hot, expands, and rises. Surrounding cooler fluid takes its place. Etc. ...
Kirchhoff law
... A doubling of CO2 (300 ppm > 600 ppm) (without any further feedbacks) would lead to an increase in downward thermal radiation by 1.2 Wm-2 (Ramanathan 1982). What would be the surface temperature response to equilibrate this additional energy a) in the tropics b)at the poles? a) Tropics: dF/dT= 6 Wm- ...
... A doubling of CO2 (300 ppm > 600 ppm) (without any further feedbacks) would lead to an increase in downward thermal radiation by 1.2 Wm-2 (Ramanathan 1982). What would be the surface temperature response to equilibrate this additional energy a) in the tropics b)at the poles? a) Tropics: dF/dT= 6 Wm- ...
New Microsoft Office Word Document
... same system externally then they are in equilibrium with each other too. FIRST LAW Energy can neither be created nor be destroyed, it can only be transformed into varius forms. SECOND LAW A reversible chemical reaction can only be reversed by introduction of an external agency THIRD LAW The entropy ...
... same system externally then they are in equilibrium with each other too. FIRST LAW Energy can neither be created nor be destroyed, it can only be transformed into varius forms. SECOND LAW A reversible chemical reaction can only be reversed by introduction of an external agency THIRD LAW The entropy ...
Black-body radiation
Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black body (an opaque and non-reflective body) held at constant, uniform temperature. The radiation has a specific spectrum and intensity that depends only on the temperature of the body.The thermal radiation spontaneously emitted by many ordinary objects can be approximated as blackbody radiation. A perfectly insulated enclosure that is in thermal equilibrium internally contains black-body radiation and will emit it through a hole made in its wall, provided the hole is small enough to have negligible effect upon the equilibrium.A black-body at room temperature appears black, as most of the energy it radiates is infra-red and cannot be perceived by the human eye. Because the human eye cannot perceive color at very low light intensities, a black body, viewed in the dark at the lowest just faintly visible temperature, subjectively appears grey (but only because the human eye is sensitive only to black and white at very low intensities - in reality, the frequency of the light in the visible range would still be red, although the intensity would be too low to discern as red), even though its objective physical spectrum peaks in the infrared range. When it becomes a little hotter, it appears dull red. As its temperature increases further it eventually becomes blindingly brilliant blue-white.Although planets and stars are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is used as a first approximation for the energy they emit.Black holes are near-perfect black bodies, in the sense that they absorb all the radiation that falls on them. It has been proposed that they emit black-body radiation (called Hawking radiation), with a temperature that depends on the mass of the black hole.The term black body was introduced by Gustav Kirchhoff in 1860. When used as a compound adjective, the term is typically written as hyphenated, for example, black-body radiation, but sometimes also as one word, as in blackbody radiation. Black-body radiation is also called complete radiation or temperature radiation or thermal radiation.