HEAT TRANSFER

~ Notes for Gartree School Pupils ~

Your name:

  • Heat is not just "hotness", but a physical process.
  • Remember earlier work about Friction and Energy.
  • Prepare for work on "Energy in the Earth System" and
    "Conservation of energy".

    Questions to think about:

  • Where can the process of Heat Transfer be seen?
  • Why is it useful to understand about Heat Transfer?
  • Does heat transfer take place at the same speed in all substances?
  • How could we find out?

    Class activity: Self Testing

    Tick the words you think you could explain at the start of the lesson

    MOLECULE

    FRICTION

    HEAT

    COLLISION

    "GLOBAL WARMING"

    CONDUCTION

    CONVECTION

    RADIATION

    KINETIC ENERGY

    METEOR SHOWER

    The Leonids

    From time to time the Earth hits a Meteor Storm!

  • These appear when we are passing through the old track of a comet.
  • Some of the comet debris will enter the Earth's atmosphere

    What is likely to happen?

  • The earth moves into the track of the comet
  • Small specks of comet dust will enter the Earth's atmosphere
  • They will be travelling VERY FAST!
  • As the dust passes through the atmosphere they will generate heat by
  • FRICTION - the collision of the atmosphere against the dust surface
  • This will cause the meteor molecules to heat up. A LOT!
  • They will burn up and vaporise - as shooting stars or fireballs

    IF the nights are clear between 16th - 27th and we are lucky, we will be able to see the result of the kinetic transfer of heat taking place in the night sky.

    But don't worry!
    Meteor showers do not generate a lot of heat in relation to the entire atmosphere.
    And meteors seldom hit the ground. They nearly always burn up.

  • Question: What are the main ways in which heat is transferred into the environment? [Clue - don't just think of human activity]

    Self Testing - end of lesson.

    Tick the ideas you could now explain in your own words:

  • HEAT energy moves from Hot to Cold until uniformly spread.
  • HEAT is spread molecule to molecule by collision.
  • Kinetic energy is energy "in motion", like the energy in a falling rock.
  • Transfer of HEAT can result in a change from solid to liquid to gas.
  • Transfer of HEAT can result in the release of other forms of energy, e.g. light.
  • Meteor showers are a demonstration of kinetic energy in action.

    The kinetic theory of heat transfer is based on the idea of energy being transferred hot to cold, molecule to molecule in the form of collisions, resulting in an even distribution of heat.

    This lesson summary is available on webpage Heat Transfer

    Space Stuff

    ©2007 Roger Parsons