1. Standard S8P2
SPS7. Students will relate transformations and flow of energy within a system.
Identify energy transformations within a system (e.g. lighting of a match).
Investigate molecular motion as it relates to thermal energy changes in terms of conduction, convection,
Determine the heat capacity of a substance using mass, specific heat, and temperature.

2. Essential Question
What are the three methods by which thermal energy is moved from place to place?

3. Thermal Energy
All matter is made up of constantly moving particles. All moving things possess kinetic energy.

4. Thermal Energy
Thermal energy is the total energy of the particles in a material. This total includes:
Kinetic energy – vibrations and movement within and between particles
Potential energy – forces that act within or between the particles (bonds)

5. Thermal Energy Thermal energy depends on:
Mass – the greater the mass, the larger the number of moving particles
Temperature – the higher the temperature, the faster the particles are moving

6. Thermal Energy
Example – Temperature as a factor

7. Thermal Energy
Example –Mass as a factor

8. Thermal Energy
Example –

9. Thermal Energy Movement
Thermal energy travels as heat from a material of higher temperature to a material of lower temperature. Thermal energy will flow from warmer objects to cooler ones until the temperature equalizes.

10. What are the three ways thermal energy can be moved from
one place to another
place?
Bill Nye on Thermal energy

11. Transfer by Collisions
Methods of
Thermal Energy Movement
Method #1
Conduction – transfer of thermal energy through matter by direct contact of particles
Transfer by Collisions

12. 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

13. Thermal Energy Movement
Methods of
Thermal Energy Movement
Conduction can take place in solids, liquids and gases.

14. Thermal Energy Movement
Methods of
Thermal Energy Movement
Matter must be present for conduction to take place!

15. Thermal Energy Movement
Methods of
Thermal Energy Movement
Examples:
Heating a pan on a stove (pan heats up by conduction) or place a spoon in a bowl of soup (spoon heats up by conduction)

17. Thermal Energy Movement
Methods of
Thermal Energy Movement
Method #2
Convection – transfer of thermal energy by bulk movement of matter

18. Thermal Energy Movement
Methods of
Thermal Energy Movement
Convection can take place in fluids (materials that flow). Liquids and gases are fluids. Currents carry less dense, warmer material up while cooler, denser material sinks.

19. The particles spread out and become less dense.
Convection
What happens to the particles in a liquid or a gas when you heat them?
The particles spread out and become less dense.
What is a fluid?
A liquid or gas.
This effects fluid movement.

20. Fluid movement
Cooler, more d____, fluids sink through w_____, less dense fluids.
ense
armer
In effect, warmer liquids and gases r___ up.
ise
Cooler liquids and gases s___.
ink

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

22. Why is it windy at the seaside?

23. 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.

24. Thermal Energy Movement
Methods of
Thermal Energy Movement
Matter must be present for convection to take place!

25. Thermal Energy Movement
Methods of
Thermal Energy Movement
Examples:
Ocean currents, wind, boiling water

26. 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.
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.

27. Temperature
Temperature is a measure of the average kinetic energy of the particles in a sample of matter.

28. Temperature
As the particles in a sample move faster and faster, the kinetic energy becomes greater and the temperature of the object rises.

29. Temperature
Temperature is measure with a thermometer.

30. Common Temperature Scales
Based on
Pure Water freezes
Pure Water boils
Fahrenheit
Salt water 32
212
Celsius
Pure water
100
Kelvin
Motion of an atom
273
373
Absolute Zero – temperature at which all atomic motion stops; ZERO on the Kelvin Scale