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A process of heat transfer that occurs when two objects are in contact with each other is?
conduction transfers hea by contact
Who stated that there is an exchange of materials when two objects come into contact with each other?
Edmond Locard. Just had a test question on him. :)
If two systems at different temperatures have contact with each other heat will flow from the system at?
40 C to 293 K Heat always flows from hot to cold.
it's sort of like diffusion, the object with the higher temperature will transfer its energy through conduction to the cooler object. after long enough, they will have t…he same temperature.
No, there will only be a spontaneous transfer of heat if the objects are at different tempratures.\n No, there will only be a spontaneous transfer of heat if the objects are …at different tempratures.\n No, there will only be a spontaneous transfer of heat if the objects are at different tempratures.\n No, there will only be a spontaneous transfer of heat if the objects are at different tempratures.\n
Heat is essentially the part of the internal energy of an object due to the disordered motion of its molecules. When two objects come in contact their molecules have a lot of… collisions at the contact surface. The faster molecules are slowed by the slow molecules while they are instead accelerated. This process cause the cold body to heat and the hot body to decrease its temperature while heat passes from the hot to the cold body. The process terminates when the temperature of the two bodies is the same and uniform across the bodies volume. This heat transfer mode is called conduction: it is the prevalent way allowing solid bodies to exchange heat when they are put in contact. In the case of liquids and gasses, conduction exists, but another phenomenon appears, that does not exist in solids: convection. This is due to the fact that liquids and gasses tends to mix when they are put in contact and, as far as hot and cold parts are mixed, they exchange heat much more effectively with respect to a contact happening only through a surface. Moreover, since heating imply the increase of volume in common condition's where the pressure is constant, this also imply decrease of density (the same matter is distributed in a greater volume, thus density decreases). This also causes hot parts of the mix to go up and cold parts of the mix to go down if gravity exists, causing further motion (called convection motions) that also favour heat exchange. However we have to take into account that normal convection motion assumes both constant pressure and gravity. In a closed container (constant volume) on the space shuttle (no gravity) the situation can be different. A third effect exists causing heat exchange between bodies at different temperature, that is not so efficient as convection and conduction, but is the only viable way in the case of object that are not in contact, like sun and earth. Every body at a temperature different from the absolute zero emits electromagnetic radiation at a frequency higher and higher while the temperature is higher and higher. Bodies at room temperature emits in the infrared while the sun in the visible bandwidth (essentially in the yellow bandwidth) and so on. If we have two bodies the hotter emits at higher frequency so that, in the radiation exchange between the bodies, it transfers more energy to the colder with respect to the energy that it receives. As a matter of fact, the number of emitted photons for unit mass is the same and the energy of the single photon is proportional to the frequency (rigorously it is true for the same number of microscopic degrees of freedom, but unit mass is explicative). Thus higher the frequency, the higher energy. This means for example that photons from sun to earth (in the visible bandwidth) are much more energetic than photons from earth to the sun (that are in the infrared bandwidth). Thus the net balance imply transfer of heat from the hot to the cold body, due to the electromagnetic emission. The heat transfer stops also in this case when the temperature of the two bodies becomes the same. The equilibrium temperature depends on how much heat the bodies can accumulate for each degree of temperature, that is by their mass and by their heat accumulation capability (called heat capacity). In the sun - earth example, if the system would be insulated, (no other heat dissipation possibility would exist beside the heat exchange between sun and earth) the earth would arrive at equilibrium to a temperature very near to the sun temperature, since the sun is much bigger than earth. In reality this does not happen since the system is not insulated and the earth dissipates towards the open space (much colder than earth) the heat received by the sun. Thus a dynamic equilibrium is reached where the earth is at an equilibrium temperature and the heat received by the sun counterbalance exactly the heath dissipated towards the outer space.
when two cold objects are rubbed against with each other...
Which method of heat transfer can take place if two objects at different temperatures are placed without touching each other in a vacuum?
Heat doesn't travel through a vacuum. The energy could be changed to light and radiate across the gap, so that would be radiation.
You can do this by the 3 ways of transferring heat. Conduction, Radiation, and Convection. You can use conduction by putting something between the 2 objects, and then the thin…g between will heat up depending on the temperature of the object, and the other object will heat up as well. You can use radiation by using waves. That is how the sun heats the Earth up. It sends waves that get trapped inside earth's atmosphere and get absorbed into the ground and given off by heat. That last way is through convection. An example of this is steam. It is given off by a boiling liquid and is hot.