What are the three ways heat is transferred?

Answer 1

Conduction - a teaspoon dipped in hot water

When one end of a rod is heated, the atoms [in the rod above the flame] vibrate faster, bump into the neighbouring atoms and start them vibrating. In this way, the atoms conduct heat from the hot end to the cool end. But during the process, the atoms themselves do not move from one end of the rod to the other.

Similarly, heat can be transferred between two bodies e.g., from a hot drink into and along a metal spoon.

Conductionis the transfer of heat as a result of the direct contact of rapidly moving atoms through a medium or from one medium to another, without movement of the media.

Materials that allow heat to travel through them in this way are called conductors. Metals are good conductors of heat. Non-metals such as plastic, clay, wood and paper are poor conductors of heat; they are also called insulators.

Convection - a pot of boiling water

Convection occurs when a liquid or gas is in contact with a solid body at a different temperature and is always accompanied by the motion of the liquid or gas. In the kettle, hot water rises and cold water descends until all the water is at the same temperature. In the atmosphere, convection results in the movement of hot and cold air ... winds!

Convection is the transfer of heat by the physical movement of the heated medium itself. Convection occurs in liquids and gases but not in solids.

Radiation - how the sun's heat reaches the Earth's surface

The sun cannot transfer heat to earth by conduction [because there is no physical contact with the earth] or convection [because there is no liquid or gas between them]. The sun heats our earth by radiation which does not require contact or the presence of any matter between them.

Radiation is the transfer of heat in the form of waves through space [vacuum]. Dull black surfaces are better than white shining ones at absorbing radiated heat.

An electric heater transfers heat by radiation [directly radiating its heat energy] as well as by convection. In convection, heated air near the heater rises and is replaced by cooler air and the cycle repeats thus warming up the entire room.

Answer 2

Conduction - a teaspoon dipped in hot water

When one end of a rod is heated, the atoms [in the rod above the flame] vibrate faster, bump into the neighbouring atoms and start them vibrating. In this way, the atoms conduct heat from the hot end to the cool end. But during the process, the atoms themselves do not move from one end of the rod to the other.

Similarly, heat can be transferred between two bodies e.g., from a hot drink into and along a metal spoon.

Conductionis the transfer of heat as a result of the direct contact of rapidly moving atoms through a medium or from one medium to another, without movement of the media.

Materials that allow heat to travel through them in this way are called conductors. Metals are good conductors of heat. Non-metals such as plastic, clay, wood and paper are poor conductors of heat; they are also called insulators.

Convection - a pot of boiling water

Convection occurs when a liquid or gas is in contact with a solid body at a different temperature and is always accompanied by the motion of the liquid or gas. In the kettle, hot water rises and cold water descends until all the water is at the same temperature. In the atmosphere, convection results in the movement of hot and cold air ... winds!

Convection is the transfer of heat by the physical movement of the heated medium itself. Convection occurs in liquids and gases but not in solids.

Radiation - how the sun's heat reaches the Earth's surface

The sun cannot transfer heat to earth by conduction [because there is no physical contact with the earth] or convection [because there is no liquid or gas between them]. The sun heats our earth by radiation which does not require contact or the presence of any matter between them.

Radiation is the transfer of heat in the form of waves through space [vacuum]. Dull black surfaces are better than white shining ones at absorbing radiated heat.

An electric heater transfers heat by radiation [directly radiating its heat energy] as well as by convection. In convection, heated air near the heater rises and is replaced by cooler air and the cycle repeats thus warming up the entire room.

Answer 3

Heat is transferred by Conduction, Convection, and Radiation.