Heat and Thermal Energy

tonyjk

Hello all.. I know this thread is asked a lot before and i read some of them.. but to make sure that i understand and to make like a small resume can we say: Heat is the "quantity" of the thermal energy being exchanged? i mean its like the work that is responsible for the change of the kinematic energy? thanks

Doc Al

You might find this FAQ entry helpful: What is Heat?

tonyjk

I have seen it already thank you anyway but please is my statement true?

Doc Al

Speaking loosely, that's fine.

tonyjk

sorry i got one more question : why we say for example something absorb heat or something is a source of heat?

tonyjk

http://hyperphysics.phy-astr.gsu.edu...o/heatreg.html

here they say "The heat PRODUCTION of the body under these conditions remains almost constant as the skin temperature rises. If the skin temperature drops below 37°C a variety of responses are initiated to CONSERVE the heat in the body and to INCREASE heat production. These include"

Doc Al

Heat flows from something hot to something cold. So a hot object could be considered a heat source and a cold one a heat sink.

tonyjk

I still have a question about the diurnal heat capacity? i didnt understand how we store heat in mass and than restore it?

Drakkith

I'm not quite sure what you are talking about here. Could you give a specific example perhaps?

tonyjk

http://pages.uoregon.edu/esbl/es_sit...folder/dhc.htm

its about the amount of heat that can be stored.. my question is how heat can be stored?

Drakkith

Everything stores heat. Heat anything up past room temperature and it takes time to cool down. The amount of heat stored differs depending on the specific composition of the material. The heat is stored until it is transferred from the object to something else. The time it takes to transfer that heat to the surrounding area depends on a large number of factors, some of which include composition of the object, what surrounds it to absorb the heat, how much surface area is exposed, and temperature difference. When the page you linked says "Mass", they just mean "Object", not literally heat stored AS mass. Although technically heat adds mass to an object since it increases the objects energy, but that is irrelevant for this discussion. The heat is not stored AS mass. It is stored in the vibration, oscillation, and movement of the particles that make up the object.

tonyjk

thank you.. can we say than when heat is stored the temperature of the object increases? because of oscillations and vibrations of particules?

Drakkith

Kind of. Even inside your fridge a soda is still storing heat. This is because any temperature above absolute zero has thermal energy, aka heat. It's the difference in temperature that makes heat flow from one object to another. Or more accurately, when two objects are not at equilibrium, heat will flow from both objects, but it will flow from the warmer object into the colder object at a faster rate than it flows from the colder object to the warmer. The net effect is a transfer of heat from the warmer object, heating the colder object until the two are in equilibrium.