1. Chapter 6 Thermal Energy
Section 1 Temperature and Heat

2. Are Temperature and heat
The same thing??
NO!!!

3. ARE TEMPERATURE AND HEAT
RELATED??
YES THEY ARE!!

4. Get This!
The matter around you is made up of tiny particles called what?
These particles are constantly in random motion; they are always moving!
Therefore they have kinetic energy

5. The faster something moves the more kinetic energy it has

6. They move faster Do particles in hot objects
move slower or faster than the
particles in cold objects?
They move faster

7. What is Temperature?
The measure of the average kinetic energy of the particles in the object
As temp the speed of the particles

8. What is the SI unit of temperature?
Kelvins which is represented by a K

9. Why does cold butter become softer when it is left sitting out at room temperature?
Because the particles in the air have more kinetic energy and collide with the slow moving particles in the cold butter

10. The particles in the butter also have potential energy. Here’s why…
The particles in butter are attracted to each other
When they are separated, they have potential energy

11. Thermal Energy
This is the sum of the kinetic and potential energy of all the particles in an object

12. Fun Fact
How does your body maintain its internal temperature??
By shivering!

13. Thermal Energy and Temperature
THEY ARE RELATED
When the temperature increases, the kinetic energy of the particles increases
Thermal energy is the SUM of kinetic energy and potential energy and therefore it will increase when temperature increases

14. Thermal Energy and Mass
Does the size of an object affect the thermal energy of the object?
Why yes it does!

15. Heat
The thermal energy that flows from something at a higher temperature to something at a lower temperature.
It is a form of energy and what is
energy measured in??

16. Example Making ice cream… Yum Heat flows from the warmer ice cream
Ingredients to the colder salt and ice mixture.
The liquid ingredients get cold enough to form solid ice cream while the ice becomes warm and melts.

17. Specific Heat
The amount of heat that is needed to raise the temperature of 1 kg of some material by 1°C
This is measured in J/(kg °C)
Table 1 p. 161 lists the specific heat of certain materials

18. Why is water used as a coolant?
It has a high specific heat and therefore can absorb heat without a large change in temperature.

19. Changes in Thermal Energy
Equation:
Q = m(Tf – Ti)C

20. Example
Find the change in thermal energy of a 20 kg wooden chair that warms from 15°C to 25°C if the specific heat of wood is 700 J/(kg°C).

21. Chapter 6 Thermal Energy
Section 2
Transferring Thermal Energy

22. Thermal Energy is transferred in 3 ways:
Conduction
Convection
Radiation

23. The transfer of thermal
What is conduction??
The transfer of thermal
Energy by collisions
Between the particles
In matter

24. So…
Thermal Energy is transferred by fast moving particles colliding with slower moving particles. When thermal energy is transferred by conduction NO matter is moved.

25. What do these things have
What are some good
Conductors??
What do these things have
In common??

26. Convection
The transfer of thermal energy in a fluid by the movement of warmer and cooler fluid from place to place

27. Convection Warmer fluid is less dense than cooler fluid
So, think of a lava lamp
What happens?

28. Convection
The warmer fluid rises to the top until it cools and then it will sink back down to the bottom

29. Earth if there is no matter In space for it to travel
How does the heat
From the sun reach
Earth if there is no matter
In space for it to travel
Through??

30. Through Radiation! The transfer of energy by electromagnetic waves
No matter is needed
Called radiant energy

31. What are some ways heat flow can be controlled?

32. Insulators Material in which heat flows slowly Examples: Wood Plastic
Fiberglass (think of the pink insulation in your house)
Air

33. Draw, Label, and Color!
p. 170 Figure 12 Draw, label, and color the thermos

34. Chapter 6 Thermal Energy
Section 3
Using Heat

35. Types of Heating Systems
Forced-Air System
*Most commonly used system today
p. 172 Fig. 13

36. Types of Heating Systems
2. Radiator Systems Fuel is burned in a central furnace and heats a tank of water. Pipes carry the hot water to radiators in a building. The thermal energy from the water is transferred to the air by conduction and spreads through the room by convection. Then the cooled water flows back down the pipes and back into the water tank.

37. Types of Heating Systems
3. Electric Heating Systems In this system electrically heated coils are placed in floors and in walls. They heat the surrounding air by conduction. Heat is distributed throughout the room by convection.

38. Solar Heating *There are two types of solar heating systems
Passive solar heating systems
Active solar heating systems

39. Passive Solar Heating
Materials absorb radiant energy (heat) from the Sun during the day. At night the building cools The thermal energy absorbed by the materials is released and helps keep the room warm.

40. Active Solar Heating
These use solar collectors that absorb radiant energy from the Sun. *The solar collectors are the GIANT black panels you sometimes see on roofs. The black panels heat water in pipes and this heated water is transferred to radiators throughout the house. The cool water then returns to the solar panel.

41. Thermodynamics
The study of the relationship between thermal energy, heat, and work
There are two laws of thermodynamics:
1. First Law of
Thermodynamics
2. Second Law of Thermodynamics

42. First Law of Thermodynamics
The increase in thermal energy of a system = the work done on the system + the heat transferred to the system
Basically: To temperature add heat, do work on the system, or both

43. Second Law of Thermodynamics
Heat will not flow from a cool object to a warmer object unless work is done
Heat

44. FYI Heat Engine Device that converts heat into work Example:
Car engine *Only about 25% of heat released by gasoline is converted to work
FYI

45. What type of combustion
engine is in a car?

46. What type of combustion
engine is in a car?
An Internal Combustion Engine

47. What is the human coolant?
SWEAT!

48. Explain how either a
Refrigerator or air
Conditioner works.