Thermodynamic temperature straightforward; for instance, calculating how a temperature change affects the pressure inside an automobile tire. If the tire has a cold pressure of 200 kPa-gage , then in absolute terms (relative to a vacuum), its pressure is 300 kPa-absolute. Room temperature ("cold" in tire terms) is 296 K. If the tire temperature is 20 °C hotter (20 kelvins), the solution is calculated as = 6.8% greater thermodynamic temperature "and" absolute pressure; that is, a pressure of 320 kPa-absolute, which is 220 kPa-gage. The thermodynamic temperature is defined by the ideal gas law and its consequences. It can be linked also
Absolute magnitude unit (AU) from both the Sun and the observer, and in conditions of ideal solar opposition. In fact, one has to take into account that Solar System bodies are illuminated by the Sun, therefore the magnitude varies as a function of illumination conditions, described by the phase angle. This relationship is referred to as the phase curve. The absolute magnitude is defined for the ideal case of phase angle equal to zero. To convert a stellar or a galactic absolute magnitude into a planetary one, subtract 31.57. A comet's nuclear magnitude () is a different scale and can not be