Various forms and Sources of Energy Form of energy Electrical energy Light energy Heat energy Sound energy Energy exists in many forms. Kinetic energy Potential energy Chemical energy Nuclear energy
1. Condition 2. Situation
Heat flow and its effects Showing the effects of heat energy on solids, liquids and gases A Solid 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
B Liquids 1.Put the flat-bottomed flask into the hot water What happen to the level of coloured water in the glass tube 2.Put the flat bottomed flask into the cold water What happen to the level of coloured water in the glass tube 4.What conclusion can you make from your observation
Heat flow 1.Heat can flow from one place to another. It can flow in three different ways i. Conduction iii. Radiation ii. Convection 2.Conduction is the flow heat through solid 3.Convertion is the flow heat through liquids and gases 4.Radiotion is the flow of heat through vacuum 7.5 Showing how heat flow in three different way Conduction A • Prepare a 50 cm long iron rod, By using wax, stick five thumbtacks on the rod • at 5 intervals 2. Clamp the iron rod to a retort stand 3.Heat the free end of the iron rod i. What do you observe ii. What is the function of the fireproof board 4. What conclusion can you make from your observation
B Convection i. Liquids 1.Tear a piece of paper into small piece 2.Put the small pieces into the water in a beaker 3.Heat the water in the beaker What do you observe 4. What is your conclusion? ii. Gases 1.Prepare the apparatus as shown 2. Light the candle and the rop What do you observe 3. What is your conclusion? C Radiation 1.Prepare the apparatus as shown 2.Place the thermometer about 10 cm from the bulb 3.Swith on the vacuum pump 4.Observe the reading of thermometer 5.Swith on the bulb 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
Thermometer Hot water Metal can Rubber band styrofoam Aluminium 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? 5. Which materials is not a heat insulator? 6 . Is your smart guess true? 7.What is your conclusion? 8.
CHANGE OF STATE - By heat energy Condensation Boiling Gases Sublimation Evaporation melting Freezing liquid solid Sublimation ABSORB / RELEASE HEAT ? 1.Crystal iodine, Dry ice and naphthalene Condensation 1.Rain, clouds and Droplet at glass contains ice.
Application of the Principle ofExpansion and Contraction of Matter The principle of expansion and contraction is commonly applied in daily life • 1.Mercury in thermometer • Mercury is a good heat conductor. • It expand rapidly when it absorbs only a little heat iii. When the temperature drops. The mercury contract and the level of mercury in the glass tube drops 2. Bimetallic strip in a fire alarm 2. Fire alarm • When there is a fire, the bimetallic is heated. As the brass bar expands • more than the iron bar ii. The bimetallic strip bends towards the contact screw. The circuit is complete and the fire alarm will ring
Gap in railway track Gap 3. The gap is allow the track to expand during very hot today in railway track 4. You can loosen the cap easily when you dip the cap of the bottle into hot water for a few minute Gap for expand Fixed end roller 5. 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
Renewable and non-renewable energy advantages disadvantages renewable Non renewable
Penutup 1. Baca Surah Al-`Ashr 2. Tasbih Kifarah.