1. Energy Transfer and Interactions of Matter and Energy
6.P.3

2. Question
If a cup of hot coffee and a red popsicle were left on the table in this room what would happen to them? Why?
The cup of coffee will cool until it reaches room temperature. The popsicle will melt and then the liquid will warm to room temperature.

3. In this lesson you will revisit:
The way in which heat behaves.
The energy transfer methods:
conduction
convection
radiation
How to reduce heat losses from your home.

4. Let’s Review: Measuring Heat Heat is measured with a thermometer.
Celsius
Freezing: 0°
Boiling: 100 °
Fahrenheit
Freezing: 32 °
Boiling: 212 °

5. What Does Heating or Cooling Do to Materials?
Melting: Solid matter changes its state to liquid.
Freezing: Opposite process of melting is called freezing.
Liquid matter loses heat and changes its state to solid.
Boiling: Liquid matters gain heat and change their states to gas.

6. Energy can be transferred from one system to another in different ways:
Thermally: when a warmer object is in contact with a cooler one
Mechanically: when two objects push or pull on each other over a distance
Electrically: when electrical source such as a battery or generator is connected in a complete circuit to an electrical device
Electromagnetic Waves

7. Molecules in Motion: Thermal energy
The motion of molecules produces heat
The more motion, the more heat is generated
Thermal energy is transferred through a material by the collisions of atoms within the material.

8. Heat Transfer
The movement of heat from a warmer object to a cooler one.
Heat flows through materials or across space from warm objects to cooler objects, until both objects are at equilibrium (balanced).

9. Heat Transfer Heat always moves from a warmer place to a cooler place.
Hot objects in a cooler room will cool to room temperature after the hot object transfers some of their heat to the cold object.
Cold objects in a warmer room will heat up to room temperature.

10. Heat Transfer Cont.
Therefore warm things lose heat and cool things gain heat until they are all at the same temperature.
Example: Ice cube is put in a glass of warm water. Ice cube gains heat from the water and the warm water loses some heat.
Eventually the ice will melt and the water will be at an even temperature

11. Heat Transfer Methods Conduction Convection Radiation
A warmer object can warm a cooler object by contact (close/touching) or at a distance (far away)
Conduction
Convection
Radiation

12. Conduction
Conduction involves the transfer of heat through direct contact
Heat travels through solids primarily by conduction.
Over time, thermal energy tends to spread through a material and from one material to another if they are in contact (conduction)

13. Conduction
When you heat a metal strip at one end, the heat travels to the other end.
As you heat the metal, the particles vibrate, these vibrations make the adjacent particles vibrate, and so on and so on, the vibrations are passed along the metal and so is the heat. We call this?
Conduction

14. Convection
Takes place in liquids and gases as molecules move in currents
Heat rises and cool settles to the bottom.
It continues in an up and down movement: warm rising and cool sinking (currents).
These currents are in air, water, and other fluids

15. Water movement Cools at the surface Convection current Hot water rises
Cooler water sinks

16. Where is the freezer compartment put in a fridge?
Cold air sinks
Where is the freezer compartment put in a fridge?
Freezer compartment
It is warmer at the bottom, so this warmer air rises and a convection current is set up.
It is put at the top, because cool air sinks, so it cools the food on the way down.

17. Why are boilers placed beneath hot water tanks in people’s homes?
Convection questions
Why does hot air rise and cold air sink?
Cool air is more dense than warm air, so the cool air ‘falls through’ the warm air.
Why are boilers placed beneath hot water tanks in people’s homes?
Hot water rises.
So when the boiler heats the water, and the hot water rises, the water tank is filled with hot water.

18. Radiation
Radiation is energy that travels across distances in the form of electromagnetic waves.
Heat is transferred through space
Energy from the sun being transferred to the Earth
Light and other electromagnetic waves can warm objects.
How much an object’s temperature increases depends on:
how intense the light striking the surface
how long the light shines on the object
how much light is absorbed.

19. ? RADIATION How does heat energy get from the Sun to the Earth?
There are no particles between the Sun and the Earth so it CANNOT travel by conduction or by convection. ?

20. The sun is a major source of energy for changes on the earth’s surface.
The sun loses energy by emitting (releasing) light.
A tiny fraction of the light reaches the earth, transferring energy from the sun to the earth.
The sun’s energy arrives as light with a range of waves:
Infrared Light: longer wave
Visible Light: visible wave
Ultraviolet Light: shorter wave
Radiation

21. Radiation Radiation travels in straight lines True/False
Radiation can travel through a vacuum
Radiation requires particles to travel
Radiation travels at the speed of light

22. ELECTROMAGNETIC SPECTRUM

23. Why are houses painted white in hot countries?
Radiation questions
Why are houses painted white in hot countries?
White reflects heat radiation and keeps the house cooler.
Why are shiny foil blankets wrapped around marathon runners at the end of a race?
The shiny metal reflects the heat radiation from the runner back in, this stops the runner getting cold.

24. Heat Transfer Song

27. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

28. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

29. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

30. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

31. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

32. Please create your own definitions for the following words based on the picture.
Convection
Conduction
Radiation
Copyright © 2010 Ryan P. Murphy

33. 1. Which of the following is not a method of heat transfer?
A. Radiation
B. Insulation
C. Conduction
D. Convection

34. 2. In which of the following are the particles closest together?
A. Solid
B. Liquid
C. Gas
D. Fluid

35. 3. How does heat energy reach the Earth from the Sun?
A. Radiation
B. Conduction
C. Convection
D. Insulation

36. 4. Which is the best surface for reflecting heat radiation?
A. Shiny white
B. Dull white
C. Shiny black
D. Dull black

37. 5. Which is the best surface for absorbing heat radiation?
A. Shiny white
B. Dull white
C. Shiny black
D. Dull black