Lesson ten Text: Heat transfer

I. Read and translate using the vocabulary given below:

Heat is a form of energy transported from one body to another because of a temperature difference. When two bodies at different temperatures are brought into contact, the warmer body will be cooled and the colder body will be warmed. In this case, heat is said to flow from the hot body to the cold body by conduction. The molecules of the hot body, being at a higher temperature, have a higher level of kinetic energy then do the molecules of the cold body. Thus, energy is transferred through the molecules from the hot body to the cold body. The energy being transferred is called heat while it is flowing from the hot body to the cold body. The energy received by the cold body increases its temperature and may be stored in its molecules as an increase in molecular or internal energy.

Heat may also be transferred from one body to another through space by means of radiation. Heat is received from the Sun by any body which is exposed to the rays of sun. The molecules of any substance at high temperature emit waves of energy which travel through the air with the speed of light. They differ from light waves only in their wave lengths. The radiant energy may be absorbed and reflected by a body upon which it falls. Upon absorption, the radiant energy is stored as molecular energy in the body and a rise of temperature takes place.

Heat may be transferred from one body to another body at a distance from the first one by means of convection. In this case, a fluid is heated or cooled by conduction through contact with one body after which the fluid flows to another place where heat is transferred between moving fluid and the second body. For instance, heat is transferred by conduction from the hot metal surface of a stove to a stream of moving air, the temperature of which is increased. The heated air is then transported to a room in which the moving warm air transfers heat by conduction to the objects in the room. When heat is transferred by convection, a fluid transports the energy from one body to another through the movement of a fluid.

because of difference to bring into contact to cool is said to to flow thus to transfer to receive to increase internal through by means of object

благодаря разница, различие соединять охлаждать говорят, что течь, перетекать таким образом передавать получать увеличивать внутренний через, посредством при помощи предмет

to be exposed rays to emit waves speed length to be absorbed to be reflected to fall (fell, fallen) to store to take place rise stream stove

подвергаться лучи выделять, издавать волны скорость длина поглощаться отражаться падать хранить происходить подъём, увеличение поток плита, печь