Temperature THE AVERAGE KINETIC ENERGY OF AN OBJECT Average motion energy Thermal Energy THE TOTAL KINETIC POTENTIAL ENERGY IN AN OBJECT Energy of stored bonds motion Temperature Reference Points ID: 421962
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Slide1
Thermal EnergySlide2
Temperature
THE AVERAGE KINETIC ENERGY OF AN OBJECT.
Average motion energy
Thermal Energy
THE TOTAL KINETIC + POTENTIAL ENERGY IN AN OBJECT.
Energy of stored bonds + motionSlide3
Temperature Reference Points
Freezing Point of Water
0 °C or 32°F
Boiling Point of Water
100°C or 212°FSlide4
0 100
Temperature (°C)
212
32
Temperature (°F)
Temperature Conversions
T
K
= Temperature in Kelvin
T
C
= Temperature in °C
T
F
= Temperature in °FSlide5
Temperature Conversions
Slide6
HEAT TRANSFERSlide7
Which object has the greatest temperature?
Which object has the greatest average kinetic energy?
Which object has the greatest total kinetic energy?
Which object has the greatest Thermal Energy?
Which object, left on its own, in outer space, has the greatest heat?
Which object, connected to the table, has the greatest heat transfer?
A.
97°C
50
mL
B.
7°C1 L
C.-2°C1000 kL
D.None of theseSlide8
Heat
HEAT = THERMAL ENERGY THAT IS
TRANSFERRED
FROM ONE OBJECT TO ANOTHER.
HEAT ALWAYS FLOWS FROM THE HIGHER TEMPERATURE TO THE LOWER TEMPERATURE
Touch the leg of your chair and the leg of your desk. Which one is colder?Slide9
Pizza Capacity
Think and Explain?
When I throw my pizza into the microwave to warm it up, it isn’t the same temperature throughout. Why?Slide10
Heat Capacity
All substances will change temperature as they gain thermal energy.
HEAT CAPACITY = THE AMOUNT OF TEMPERATURE CHANGE TO A HEATED OBJECT DEPENDS ON THE OBJECT AND THE MASS.Slide11
Modes of Heat Transfer
The three methods of Heat Transfer
CONDUCTION
CONVECTION
RADIATIONSlide12
Conduction
CONDUCTION = THERMAL ENERGY TRANSFERRED BY THE COLLOSIONS OF PARTICLES
CONDUCTION
REQUIRES CONTACT
It is an exchange of energy between atoms and electrons by collisions
Less energetic particles gain energy during collisions with more energetic particles.
Slide13
Materials
Listed are common materials. Better conductors have a higher thermal conductivity
Demo -
POOR CONDUCTOR = GOOD INSULATORSlide14
Conduction Examples
Why is the tile cold and the carpet feel
warm?
Because the tile is a better conductor and it has a greater heat capacitySlide15
Convection
What is convection?
THERMAL ENERGY TRANSFERRED BY A CURRENT OF FLUID
REQUIRES A FLUID(Gas/Liquid)
When
the movement results from differences in density, it is called
natural convection
When the movement is forced by a fan or a pump, it is called forced convectionSlide16
Convection Heating
An example of natural
convection
Explain what is happening
Water Temp DemoSlide17
Convection Current Example
What is the forced convection?
What is the natural convection?Slide18
Weather –
due to natural convectionSlide19
Radiation
RADIATION = THERMAL ENERGY TRANSFERRED BY ELECTROMAGNETIC WAVES
RADIATION DOES
NOT
REQUIRE CONTACT
All objects radiate (give off) energy continuously in the form of electromagnetic waves due to thermal vibrations of the moleculesSlide20
Thermal Expansion
When an object is heated, it’s particles speed up and spread apart, making the object expand.
Demo -
Uses: Cavities, Bridges, Sidewalks Lines
Downsides - potholesSlide21
Radiation example
No physical contact is necessary
The
electromagnetic waves
carry
the energyThe heat transfer cannot be accounted for by conduction or convection (thru space)Slide22
States of MatterSlide23
Picture
Volume
Shape
Kinetic Energy
Inter-molecular Force
Gas
Liquid
SolidSlide24
Phase Summary
Picture
Definite Volume
Definite Shape
Kinetic Energy
Inter-molecular Force
Gas
No
No
High
Sometimes bounce off one another
None
Liquid
Yes
No
Medium
Roll, Bounce off one another
Weak
Solid
Yes
Yes
Low
Shake back and Forth
StrongSlide25
States of Matter Notes
These are found online at
http://prezi.com/_2quyv8zpnzq/notes-states-of-matter
/
(Look at these or you’ll be sorry).Slide26
Deposition = Frost
Condensation
Amorphous
Definite Shape
No Definite Shape
Fluid
Molecules in motion
Vaporziation
Melting
Crystalline
Freezing
Definite Volume
No Definite Volume
Least Kinetic energy
Medium Kinetic energy
Property of Viscosity
Highest Kinetic Energy
Sublimation = Dry IceSlide27
Phase Change GraphsSlide28
0 1 2 3 4 5
Thermal Energy
150
100
50
0
Temperature (°C)
Thermal Energy and Phase Changes
Freezing
Liquid
Gas
Condensation
Melting
Solid
VaporizationSlide29
Phase Change Process (S & L)
Melting – THERMAL ENERGY IS USED TO BREAK BONDS
The bonds that hold molecules in vibrating lattice structure are breaking.
The Intermolecular Forces Lessen
Freezing
– THERMAL ENERGY IS USED TO CREATE BONDS AND HOLD MOLECULES IN PLACEThe bonds that will hold molecules in position are forming
The Intermolecular Forces Increase
Melting Point – THE TEMPERATURE AT WHICH AN OBJECT EITHER MELTS OR FREEZES.Slide30
E
vaporation =
E
scape
Brant’s Maximum
Security Penitentiary for Incarcerated Dress Code Violators and Others.If the highest IQ’s escape, what happens to the average Penitentiary IQ.UpDownSameSlide31
VAPORIZATION (L – G)
EVAPORATION – A CHANGE IN PHASE FROM LIQUID TO GAS
AT THE SURFACE.
This cools the remaining liquid!
BOILING – A CHANGE IN PHASE FROME LIQUID TO GAS
BELOW THE SURFACE.This
cools the remaining liquid!
Boiling Point – THE TEMPERATURE THAT AN OBJECT VAPORIZES OR CONDENSES.Slide32
Condensation (G
L)
CONDENSATION – A CHANGE OF PHASE FROM GAS TO LIQUID.
This is a WARMING PROCESS for the liquid.
Gas
molecules strike surface of liquid and give up so much energy that they can’t stay in gaseous phaseExamples
Droplets forming on mirror
Droplets on glass of waterSlide33
C
ondensation =
C
aptured
The smart kids sneak out of a convocation in the gym and join the prison of ISS.
What happens to the average IQ of the prison?UpDownSameSlide34
Phase Changes with the Gizmo
The differences with this type of graph, and the basic phase change graph is that the time is the x-axis instead of changing
thermal energy.
Hint: In these graphs Mr. Nuetzel had an initial setup, then didn’t change any of the settings after starting it.Slide35
Phase Change Gizmo
With this setup, what will happen to the temp. graph?Slide36Slide37
Phase Change Gizmo
With this setup, what will happen to the temp. graph?Slide38Slide39
Phase Change Gizmo
With this setup, what will happen to the temp. graph?Slide40Slide41
Phase Change Gizmo
With this setup, what will happen to the temp. graph?Slide42Slide43
What’s the difference between these two graphs?Slide44
What’s the difference between these two graphs?Slide45
Phase Change Gizmo
With this setup, what will happen to the temp. graph?Slide46Slide47
Interpreting Graphs
Hint – Mr. Nuetzel didn’t keep the RATE of heat transfer constant in these graphs.Slide48
What is happening in this graph?Slide49
What is happening in this graph?Slide50
What is the difference in these graphs?Slide51
What is happening in this graph?Slide52
What is happening in this graph?Slide53
What is happening in this graph?Slide54
Acting Out Phase Changes
Get in a group of 8-12 students. You will have 2 minutes to decide how you want to act out one of the phase changes that H2O can go through with either an addition or subtraction of thermal energy.
Demonstrate your skit to the class.Slide55
Review
Discussion
Questions
Explain in detail and use the thermal energy vocabulary.
When
I throw my pizza into the microwave to warm it up, it isn’t the same temperature throughout. Why?How is the house heated?How does a thermometer work?