CHAPTER 6: Source of energy

Various forms and Sources of Energy

Light energy

Soundenergy

Nuclear energy

Chemical energy

Potential energy

Kineticenergy

Heat energy

Electrical energy

1. Condition

2. Situation

Akhir Tahun 2011

Heat flow and its effectsShowing the effects of heat energy on solids, liquids and gases

1.Place the metal ball on the metal ring

Can the metal ball pass through the ring?

2.Heat the metal ball with a Bunsen Burner. Place the metal ball on the metal ring Can the metal ball pass through the ring?3.Let the metal ball cool down to the room temperature. Place the metal ball on the metal ring again Can the metal ball pass through the ring now?

4.What conclusion can you make from your observation

A Solid

B Liquids

1.Put the flat-bottomed flask into the hot waterWhat happen to the level of coloured water in the glass tube

2.Put the flat bottomed flask into the cold waterWhat happen to the level of coloured water in the glass tube

4.What conclusion can you make from your observation

Heat flow1.Heat can flow from one place to another. It can flow in three different ways

i. Conduction ii. Convection iii. Radiation2.Conduction is the flow heat through solid3.Convertion is the flow heat through liquids and gases4.Radiotion is the flow of heat through vacuum

7.5 Showing how heat flow in three different way

1. Prepare a 50 cm long iron rod, By using wax, stick five thumbtacks on the rod at 5 intervals2. Clamp the iron rod to a retort stand3.Heat the free end of the iron rod

i. What do you observeii. What is the function of the fireproof board

4. What conclusion can you make from your observation

A Conduction

B Convectioni. Liquids

1.Tear a piece of paper into small piece2.Put the small pieces into the water in a beaker3.Heat the water in the beaker

What do you observe

4. What is your conclusion?

ii. Gases1.Prepare the apparatus as shown2. Light the candle and the rop

What do you observe

1.Prepare the apparatus as shown

3. What is your conclusion?

C Radiation

2.Place the thermometer about 10 cm from the bulb

5.Swith on the bulb4.Observe the reading of thermometer3.Swith on the vacuum pump

6. After 10 minute, observe the reading of the thermometer again

What do you observe

What your conclusion?

Convection current

1.The hotter water or gases rise because it less dense

2.The cold water or gases coming to replace the hotter water or gases

Natural phenomena involving heat flow

Natural phenomena such as sea breeze, land breeze and warming of earth by the Sun.

Cool air

Question

1.Compare the different between the initial temperature and final temperature of water in each can. What do you observe.

2.Which material allows heat to pass through it easily?3.Which materials does not allows heat to pass through it easily?4. Which materials is a heat insulator?

6 . Is your smart guess true?5. Which materials is not a heat insulator?

7.What is your conclusion?8.

Thermometer

Hot waterMetal can

styrofoam Rubber bandAluminium

CHANGE OF STATE - By heat energy

melting

FreezingEvaporation

Boiling

Subl

imat

ion

Condensation

Sublimation1.Crystal iodine, Dry ice and naphthalene

Condensation1.Rain, clouds and Droplet at glass contains ice.

solidliquid

Gases

ABSORB / RELEASE HEAT ?

Application of the Principle of Expansion and Contraction of Matter

The principle of expansion and contraction is commonly applied in daily life

1.Mercury in thermometeri. Mercury is a good heat conductor. ii. It expand rapidly when it absorbs only a little heatiii. When the temperature drops. The mercury contract and the level of mercury in the glass tube drops

2. Bimetallic strip in a fire alarm

i. When there is a fire, the bimetallic is heated. As the brass bar expands more than the iron barii. The bimetallic strip bends towards the contact screw. The circuit is complete and the fire alarm will ring

2. Fire alarm

Gap in railway track

Gap for expand

roller

Fixed end

Gap

You can loosen the cap easily when you dip the cap of the bottle into hot water for a few minute

The gap is allow the track to expand during very hot today

To allow for movement when a steel bridge expands or contract, one of its end is fixed while the other end is free to move over roller

4.

5.

3. in railway track

energy in everyday lifeconverters Energy conversion

Moving car Chemical energy kinetic energyLighted candle Chemical energy heat energy + light energyAlarm clock Potential energy kinetic energy sound energyElectric kettle Electrical energy heat energyStrecthed bow and arrow

Potential energy kinetic energy sound energy

Solar cell Light energy electrical energyBicycle dynamo Kinetic energy electrical energy light energy + heat energyTelevision Electrical energy light energy + sound energyHair dryer

Telephone

hydroelectric Potential energy kinetic energy electric energy

Renewable and non-renewable energyadvantages disadvantages

renewable

Non renewable

Penutup

2. Tasbih Kifarah.

1. Baca Surah Al-`Ashr