• Occurs at a fixed temperature
• Quick process
• Takes plave throughout the liquid
• Bubbles are formed in the liquid
• Tempertaure remains constant
• Thermal energy supplied by an evergy source

Evaporation

• Occurs at any temperature
• Slow process
• Takes place only at the liquid surface
• No bubbles are formed in the liquid
• Temperature may change
• Thermal energy supplied by the surroundings

Now you see the difference? :D

Evaporation causes cooling!

OMG LOOK (:

When you step out of the swimming pool,your body will feel cold.
Have you ever wondered why? (:

Thermal Energy from your body helps the water on the skin to evaporate.When the water evaporates,it takes away thermal energy from the surface of your skin.Hence you'll feel cold.

NOW you know why :D

HOW DOES EVAPORATION OCCUR?

• Evaporation occurs only at the surface of the liquid
• Energetic molecules escape,carrying thermal energy away
• Some molecules rebound into liquiddue to collision with the air molecules or other escaping molecules
• Less energetic molecules are then left behind in the ether.

APPLICATIONS OF EVAPORATION (!!!)

Puddles of water WILL dry up after awhile

Refrigerators uses the principles of condensation and evaporation in the cooling process to help keep its contents cold

1. Temperature

• Raising the temperature of the liquid will increase the rate of evaporation.

2.Humidity of the surrounding air

• The air is humid when there is alot of water vapour present in the air.
• Rate of evaporation decreases with increasing humidity
• Wet clothes do not dry easily if the surrounding air is damp

• Wet floors take longer to dry on humid days

3. Surface area of the liquid

• More exposed surface area,rate of evaporation increases
• This explains why wet clothes should be spread out for drying to expose to the maximum possible surface area for evaporation to take place.

4.Movement of air

• WE cool down faster in moving air than in still air.

• The moving air from the hair dryer removes the molecules of the liquid as soon as they escape from the surface of your hair.
• Hence the rate of evaporation increases when the surrounding air is moving.

5.Pressure

• Reducing the atmospheric pressure increases the rate of evaporation

6.Boiling point of the liquid

• Liquids with lower boiling points will evaporate faster.

_________________________________________

OMG YES!
I'M DONE! (:

Goodbye!
I LOVE Thermal Physics :D

YAY YAY YIPPI YAY

Hello everybody,We're going to start on chapter 9

AND IT'S GOING TO BE THE LAST CHAPTER!

Kay lets not waste anymore time,and start on work!(:

CHAPTER 9!

THERMAL PROPERTIES OF MATTER(!!)

Process of heating a beaker of water!

• We are applying thermal energy from the Bunsen flame to the water
• This thermal energy supplied to the water leads to a gain in the INTERNAL ENERGY of the water molecules

Microwave!

• A microwave oven raises the internal energy of food by making water molecules in the food vibrate VIGOROUSLY O:

Slinky! ( So fun right)

• Potential energy is stored in the slinky as it is stretched or compressed!

MELTING AND SOLIDFICATION!

Melting is when a solid changes to a liquid upon heating
Melting occurs at a definte or constant temperature for pure substances

HOW DOES A SOLID MELT

The molecules in the solid are held by strong intermolecular bonds
The bonds have to be broken to melt
Once it is broken,the molecules can now move out of their fixed position
And therefore,A change of state from solid to liquid has occured
Hence there is no change in temperature during melting

SOLIDIFICATION!

Solidification is a reverse process of melting
Changing a LIQUID ->SOLID

Freezing point!

Water freezes to form ice at 0 degrees.
Therefore this temperature of 0 degrees is called the melting point of the water.

BOILING AND CONDENSATION

Boiling is

• A pure liquid heated and changes to a vapour

HOW ABOUT CONDENSATION?

Condensation is

• A reverse of boiling
• Changes a state from vapour to liquid
• Thermal Energy is given out during condensation

HOW DOES A LIQUID BOIL?

The thermal energy is used to do work to seperate the molecules as well as push back to the surrounding atmosphere.The molecules are now much further apart with negligible intermolecular forces of attraction btween them.

And hence when this happens boiling has taken place (YAY)

Watch when you're free(!!)

11:10 PM

Chapter 7

Omg HAHAHA this video's damn retarded
Please don't stop watching just because the starting is SILLY.
Just watch the whole thing(It's related to physics for nuts!)

This one is more about Solid,liquid&gas itself(:

Chapter 8

CONDUCTION CONVECTION RADIATION

Part 1

This will take quite long to load
But It's worth the wait afterall :D

Part 2

Part 3

Last post on Chapter 8 (!)

10:39 PM

Yet again,Still on Chapter 8
But finishing soon already! :D

Common applications of convection (!)


1. Electric Kettles


The heating coil is always placed at the bottom of the kettle to aid transfer of thermal energy in water by CONVECTION.


2. Household hot water systems



The household hot water system is designed based on the CONVECTION in liquids.

3.Air Conditioners

Air conditioners is always installed near to the ceiling of a room to facilitate setting up of CONVECTION currents.
An air conditioner releases cool dry air into the room.As cool air is denser,it will tend to sink.The warm air below,being less dense,will rise and is drawn into the air conditioner where it is cooled.

Easy? :D

4.Refrigerators



They work the same way as air conditioners.

Freezing unit is usually placed at the top to cool the air and facilitate the setting up of CONVECTION currents.It will help cool the contents inside(:

Common applications of radiation (!!)

1. Teapots ( SHINY TEAPOTS :D )



Shiny surfaces are BAD emitters of radiation!
They can keep tea warm and help to keep cold liquids cool for a longer time than the black teapots(: SO BUY SHINY ONES NEXT TIME! :D

2. The greenhouse O:

• Greenhouse is used in cold climates to help plants grow better just by trapping heat (Wow)
• Infrared radiation from the sun pass through the glass roof of the greenhouse and therefore helps to warm up the soil and plants in the greenhouse.
• As the contents get warmed up,they'll start to emit infrared radiation
• The amount of infrared radiation in the greenhouse builds up over time,and hence,causes the temperature in the greenhouse to increase O:

3.Vacuum flasks!

THEY^ are designed to keep liquids hot by minimising heat loss in 4 O: Possible ways.

CONDUCTION(!)
CONVECTION(!!)
RADIATION(!!!)
EVAPORATION(!!!!)

• The stopper is usually made of plastic which is a poor conductor of heat ( GOOD! )
• Conduction through the trapped air above the liquid is minimal
• CONDUCTION & CONVECTION through the sides of the flask are prevented by the vacuum between the walls of the flask.

____________________________________

ZOMG ZOMG ZOMG.
I FINISHED CHAPTER 8!
CLAPCLAPCLAP O:

Kay I have 35 mins to do CHAPTER 9 ZOMG.
I don't wish to do shoddy work,I'LL DO NOW
Bye

2nd post on Chapter 8 O:

9:14 PM

Still on Chapter 8 (!!) Omg why so long D:

APPLICATIONS OF THERMAL ENERGY TRANSFER!(:

Spare you from words first yeah(:

Take a look at the pictures.

Cooking Utensils:

Kettles:

Soldering Iron Rods:

Heat exchangers:

They all have something in Common! And that is they are

USES OF GOOD CONDUCTORS OF HEAT ( CLAPCLAP)

Somemore peektures? :D

Sure(!!)

Handles of appliances and Utensils:

Table Mats:

Sawdust:

Wooden ladies

Woollen clothes:

Fibreglass,felt and expanded polystyrene foam:

A slide made of fibreglass ^

They are all:

USES OF BAD CONDUCTORS OF HEAT (Insulators)

Don't look down on them!

They are very useful if we want to minimise loss of thermal energy,or prevent thermal energy from being transferred quickly (Woah)

WOW (YAY!) So many pictures right.

Man my hands are tired from backspacing and scrolling ):