Q:

How does heat move?

A:

Quick Answer

Heat can be transferred from one place to another by conduction, convection, radiation or a combination of these methods. Conduction and convection involve the movement of particles, but radiation involves electromagnetic waves.

Know More

Full Answer

Conduction occurs as molecules move around and bump into one another. According to the second law of thermodynamics, faster-moving (hotter) molecules give up some of their heat energy to slower-moving (colder) molecules whenever a collision occurs. The newly heated molecules then pass some of that heat to other molecules.

Substances vary in their ability to conduct heat. Air and water are poor conductors. Metals tend to conduct heat rapidly, and asbestos conducts heat so poorly that it was used as a heat insulator.

Convection happens because when a fluid (whether liquid or gas) is heated, the portion nearest the heat source expands as it gains energy. The expanding portion becomes less dense (lighter) and is pushed upward by cooler, heavier portions of the surrounding fluid. This displacement brings the cooler portions nearer the heat source until they gain energy, become lighter and move upward in turn. The resulting movement distributes heat from the source throughout the fluid.

Heat travels by convection as long as temperature differences exist within the fluid. The movement of warm air in a room and the circulation of water in a kettle placed over a fire are examples of convection moving heat.

All objects that are warmer than absolute zero continually give off energy in the form of electromagnetic waves. A body emits heat rays as its molecules vibrate.

As the rays are emitted, the molecules of the initial body lose energy. When another body absorbs the rays, its molecules become more agitated, and it gains heat energy.

Learn more about Earth Science

Related Questions

  • Q:

    What is heat conduction?

    A:

    Heat conduction is the transfer of internal energy (microscopic kinetic and potential energy) from a region of higher temperature to one of lower temperature by the interaction of particles like atoms, molecules, ions or electrons in the intervening space. Conduction can only take place within an object or material or between two objects that are in direct or indirect contact with each other.

    Full Answer >
    Filed Under:
  • Q:

    What is an example of a high specific heat?

    A:

    An example of a high specific heat is water’s specific heat, which requires 4.184 joules of heat to increase the temperature of 1 gram of water 1 degree Celsius. Scientifically, water’s specific heat is written as: 1 calorie/gm °C = 4.186 J/gm °C.

    Full Answer >
    Filed Under:
  • Q:

    Is air a good conductor of heat?

    A:

    Air is not a good conductor of heat, as it actually serves as an insulator when it is contained in an enclosed area. Air helps to prevent heat loss, instead of transferring heat to or between surfaces.

    Full Answer >
    Filed Under:
  • Q:

    What are Earth's primary sources of heat?

    A:

    Earth's primary sources of heat are from radioactive decay, frictional heating and Earth's formation. Although Earth was created around 4.5 billion years ago, there is still leftover heat from its formation.

    Full Answer >
    Filed Under:

Explore