1. Understanding Heat Transfer, Conduction, Convection and Radiation
Standard 4b

2. What is the biggest thing in our solar system?

3. What is the biggest thing in our solar system?
The sun is so big that it is responsible for most of earth’s energy.

4. More than 100 watts of energy strike every square meter of earth every second!
That is more than 10,000 times the amount of energy that is used by human societies in a day.

5. Energy Use Ranking 1. Sun gives the earth the most energy 2
Energy Use Ranking 1. Sun gives the earth the most energy 2. Energy in the earth (radiation/heat from core) – drives plate tectonics 3. Energy used by society

6. So how does the energy from the Sun get to Earth?

7. So how does the energy from the Sun get to Earth? RADIATION
solar radiation video

8. **Heat Transfer
**Heat always moves from a warmer place to a cooler place.
Hot objects in a cooler room will cool to room temperature.
Cold objects in a warmer room will heat up to room temperature.

9. 3 mechanisms of energy transfer as heat are:
Conduction
Convection
Radiation

10. Heat Transfer Conduction, Convection and Radiation

11. Question
If a cup of coffee and a 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 cool to room temperature.

12. Conduction:
The movement of heat by touch.

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. Metals are different
The outer e_______ for metal atoms drift, and are free to move.
lectrons
When the metal is heated, this ‘Sea of electrons’ gain k_____ energy and transfer it throughout the metal.
inetic
Insulators, such as w___ and p____, do not have this ‘Sea of electrons’ which is why they do not conduct heat as well as metals.
ood
lastic

15. Why does metal feel colder than wood, if they are both at the same temperature?
Metal is a conductor, wood is an insulator. The metal conducts the heat away from your hands, the wood does not conduct the heat away from your hands as well as the metal, so the wood feels warmer than the metal.

16. EXAMPLE OF CONDUCTION
A piece of cheese melts as heat is transferred from the meat to the cheese (Contact)

17. The particles spread out and become less dense.
Heating fluids
What happens to the particles in a liquid or a gas when you heat them?
The particles spread out and become less dense.
This affects fluid movement.

18. Convection: Transfer of heat by movement of fluid or gas.
Fluid movement
Convection: Transfer of heat by movement
of fluid or gas.
Cooler, more d____, fluids sink through w_____, less dense fluids.
ense
armer
**Warmer liquids and gases r___ up.
ise
**Cooler liquids and gases
s___.
ink

19. Convection: transfer of heat by a moving fluid or gas
Water movement
Cools at the surface
Convection current
Convection: transfer of heat by a moving fluid or gas
Cooler water sinks
Hot water rises

20. Why is it windy at the seaside?

21. Cold air sinks What part of a two story house is usually the warmest?
2nd floor because the warm air rises and the cold air sinks.

22. The third method of heat transfer
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.
RADIATION - Transfer of heat by light ?

23. RADIATION Radiation is the transfer of energy by electromagnetic waves
Radiation does NOT require matter to transfer thermal energy
Radiation = Radiates (heat escaping the sun)

24. Radiation May Come From Other Sources
Have you ever sat too close to a campfire while cooking marshmallows? You are enjoying the warmth ….. only to notice that your skin is really warm?

25. Examples of RADIATION
Fire
Heat Lamps
Sun

26. 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

27. Heat transfer through the atmosphere3 4 2 1

28. Why does hot air rise and cold air sink?
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.
What makes the Earth’s tectonic plates move?
Convection currents in the mantle

29. 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 from getting too cold.

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

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

32. 3. How does heat energy reach the Earth from the Sun?
A. Radiation
B. Conduction
C. Convection
D. Insulation
types of heat transfer video

33. Absorb
Absorb means to take in, like a sponge absorbs water.

34. Reflect
Reflect means to bounce back, like a mirror reflects light.

35. 5%
20% 5%
20%
50%
50%

36. Cold Air sinks, it is more dense than hot air.

37. Determine if the heat will be transferred by conduction, convection or radiation.
Ice melting in somebody’s hand.

38. Determine if the heat will be transferred by conduction, convection or radiation.
The hand touching the needle in the fire.

39. Determine if the heat will be transferred by conduction, convection or radiation.
Heat movement from the stove top to the bottom of the pan.

40. Determine if the heat will be transferred by conduction, convection or radiation.
The woman is drying her hair with a hair dryer.

41. Determine if the heat will be transferred by conduction, convection or radiation.
This is a thermal image. It was taken with a heat sensing camera.

42. Determine if the heat will be transferred by conduction, convection or radiation.
The air conditioner is moving cool air through the house and the furnace pumps warm air.

43. Determine if the heat will be transferred by conduction, convection or radiation.
The fluid inside the lava lamp rising upwards.

44. Determine if the heat will be transferred by conduction, convection or radiation.
The man is warmed by the energy from the heat lamp.

45. Determine if the heat will be transferred by conduction, convection or radiation.
The cat is warmed by the heat of the fire.

46. Determine if the heat will be transferred by conduction, convection or radiation.
Steam is created by the tea kettle and warms the cat.

47. How is heat transferred at 1, 2 and 3?
3. The glove touches a metal rod that is in the fire
Warm air heats the hands
2. Heat from the fire warms the hands

48. ENERGY TRANSFER
_________ = energy travelling through empty space
________ = energy (heat) moving from one substance to another when those two substances are touching
_______ = energy (heat) moving throughout a gas or liquid.

49. Solar radiation travels through space and heats up Earth’s surface.
Notes:
How heat moves in the atmosphere:
Solar radiation travels through space and heats up Earth’s surface.
Hot surface heats up the bottom part of the atmosphere by conduction.
Once the air gets hot it rises, and convection starts.

50. Determine if the heat will be transferred by conduction, convection or radiation.
Popcorn heated in a microwave oven

51. Determine if the heat will be transferred by conduction, convection or radiation.
Popcorn heated in an air popper

52. Determine if the heat will be transferred by conduction, convection or radiation.
Popcorn heated in a Jiffy Pop foil container on the stove (no oil).

53. Determine if the heat will be transferred by conduction, convection or radiation.
This is a thermal image of a bunny rabbit.

54. How heat is transferred on earth
Bill Nye clip
3. Air molecules rise and spread their heat by convection
radiation
Hot air molecules rise
convection in air clip
Cool air molecules sink
2. Air molecules touch the ground and get warm by conduction.
1. Ground gets heated by sun’s radiation

56. Conduction

57. Conduction

58. Conduction

60. Energy Budget Video

61. Warming the atmosphere video

62. Photosynthesis- process by which plants take water, carbon dioxide, and sunlight to make sugar and oxygen.

63. H2O + CO2 + sunlight sugar + O2

64. According to the picture, is sunlight being absorbed or released?

65. According to the picture, what is being absorbed by the leaf and what is being released by the leaf?

66. No animal life on Earth without plants and bacteria that can photosynthesize.
PS v

69. 25%
15%
50%

70. conduction

71. convection

72. Radiation

73. Sun/weather animations

74. Vocabulary due March 30 Atmosphere Conduction Convection Radiation
Ozone
Photosynthesis
Greenhouse Effect
Absorb
Reflect
Stratosphere
Provide a definition and picture for each word.

75. Object A – between the turtles foot and the rock
Object B – turkey vulture gliding on a thermal