TEMPERATURE Temperature (T, t,or) is a measure of the hotness or coldness of a body.
It is a scalar quantity with an SI unit of kelvin (K).
When temperature is measured in kelvin, it has the symbol T, indicating that it is the absolute temperature.Although kelvin is the SI unit of temperature,we often use degree Celcius (°C) as both units are the same size and there is a fixed relationship between them.When temperature is measured in degree Celcius is has the symbol t. When we deal with temperature in numeric calculations, we generally use the symbol (either K or C is a suitable unit). The Greek letter delta ( ) is used to indicate ‘change in...’ therefore ‘change in temperature’ is denoted by ‘ ’.
¢ ¢u Heat
HEAT Heat (Q) is the energy due to the movement of the molecules within the body.
As with any form of energy, it is a scalar quantity with an SI unit of joule ( J). It causes a rise in temperature when added or a fall in temperature when withdrawn.
Difference Between Heat and Temperature
Temperature is a measure of the level of hotness or coldness of a body; heat is the amount of thermal energy in the body.
Two bodies can have the same temperature but a different amount of heat in them. For example, a swimming pool and a beaker of water both at 20C will have different amounts of heat.
Heat will travel from one body to another if there is a difference in temperature between them. It will travel from the higher temperature (hotter body) to the lower temperature (colder body).
Temperature Scale
All scales for temperature must be based on the following principles.There must be: • two fixed points that can be easily reproduced
• a division of the fundamental interval (between the two fixed points) into a more practical size (a number of parts of equal size).
