Student Handout Science F1

SCIENCE TUSYEN 1. FORM 1. Chapter 3. MATTER

Chapter 4. DIVERSITY OF RESOURCES ON EARTH

SCIENCE TUSYEN 3. FORM 1. Chapter 5. AIR AROUND US

SCIENCE TUSYEN. FORM 1. CHAPTER 6. SOURCES AND FORMS OF ENERGY

SCIENCE TUSYEN FORM 1 CHAPTER 7. HEAT AND ITS TRANSFER

VARIOUS FORMS OF ENERGY CHEMICAL ENERGY

HEAT ENERGY

ELECTRIVAL ENERGY

POTENTIAL ENERGY

KINETIC ENERGY

SOUND ENERGY

ENERGY LIGHT ENERGY MECHANICAL ENERGY

NUCLEAR ENERGY

OXYGEN IN AIR

RUSTING PHOTOSYNTHESIS

ANIMALS AND HUMANS

GREEN PLANTS

CARCASSES

FOSSIL FUELS

DECOMPOSITION RESPIRATION

COMBUSTION

CARBON DIOXIDE IN AIR

METALS

SOURCES OF ENERGY ON EARTH

RENEWABLE

NON RENEWABLE

BIOMASS SOLAR HYDRO WIND GEO THERMAL WAVES

FOSSIL FUELS NUCLEAR

COAL PETROLEUM

NATURAL GAS

EXAMPLES OF ENERGY CONVERTER ENERGY CONVERTER RADIO TELEVISION

ENERGY CONVERSION Electrical energy

GAS STOVE

Electrical energy energy Chemical energy

ELECTRIC FAN

Electrical energy

BICYCLE Kinetic energy DYNAMO energy ELECTRIC IRON Electrical energy HAIR-DRYER ELECTRIC RICE COOKER LIGHT BULB

sound energy light energy heat energy

light energy

kinetic energy electrical energy

light

heat energy

Electrical energy kinetic energy energy sound energy Electrical energy heat energy Electrical energy energy

sound

heat energy

heat

light

THE PRINCIPLE OF ENERGY CONSERVATION

~ Energy cannot be created or destroyed

~ Energy can only be converted from one form to another

ENERGY IS CONSERVED Amount of energy Amount of energy before conversion after conversion

PROCESSES AND ENERGY CONSERVATION LIGHT ENERGY (from the sun) CHEMICAL ENERGY (in food)

PHOTOSYNTHESIS

RESPIRATION

CHEMICAL ENERGY (in food) HEAT ENERGY + WATER + CARBON DIOXIDE

COMPARISON BETWEEN CONDUCTION, CONVECTION AND RADIATION CONDUCTION ~ Transferred by particles that vibrate and collide with other particles ~ Occurs in solids, liquids and gases but most effective in solids ~ Does not occur in a vacuum ~ rapid process

CONVECTION

RADIATION

~ Transferred by particles that move and form a convectional current

~ Radiated by a hot body to surrounding

~ Occurs in fluids Like liquids and gases most effective

~ Occurs without any medium

~ Does not occur in a vacuum ~ slow process

~ Can occur in a vacuum ~ rapid process (light Speed)

CAR’S RADIATOR ~ to remove heat produced in engine by convection through water in the radiator

THERMOS FLASK ~ vacuum space prevent heat loss by conduction and convection ~ silver layered prevent heat loss by radiation

TO WARM BODY ~ fire – to warm our bodies prevent heat transfer by radiation from our body to surrounding

USAGE OF THE PRINCIPLE OF HEAT TRANSFER IN SOLVING PROBLEMS HOT ROOM 1. the ventilation system of a building ~ hot air rises out through upper section (air holes) 2. air conditioner ~ apply principle of convection, fixed at upper section

COLD ROOM Air heater and heating system ~ apply principle of convection, fixed at lower Section. Hot air which produced moves up while the cold air moves down

METHODS OF HEAT TRANSFER CONDUCTION: ~ Heat transfer through solid from a high temperature to a low temperature Examples of good conductors are metal. Copper Aluminium Iron decrease

CONVECTION: ~ Heat transfer in a fluid from A hot to a less hot area

RADIATION: ~ Heat transfer from a heat source to its surroundings without the need of medium (air or vacuum)

~ Hot fluid (less dense) move up ~ Cold fluid (more dense) move down

~ Can be absorbed or reflected ~ travel at speed of light

CONDUCTORS

AND

INSULATORS

Materials that conduct heat easily

Materials Conduct

Examples: Metals ~ copper, iron mercury, aluminium

Examples: Wood, plastic, rubber, water and air

Applications: ~ cooking utensils ~ radiator coil in vehicle ~ mercury – thermometer ~ wire gauze (steel) ~ heating coil – electric kettle ~ soldering iron – made of copper ~ Davy safety light

that heat

do not easily

Applications ~ handles of cooking utensils ~ polystyrene – food containers ~ fibreglass –refrigerators ~ sawdust – prevent ice melt ~ fur clothing – keep body warm ~ blanket – keep body warm ~ igloo ~ sleeping bag

NATURAL APPLICATION OF THE PRINCIPLE OF CONVECTION LAND BREEZE ~ at night, land cools faster than sea ~ hot air from the sea rises and it is replaced by cold air from the land

SEA BREEZE ~ during day time, land heats up faster than sea ~ hot air from the land rises and it is replaced by cold air from the sea

NATURAL APPLICATION OF THE PRINCIPLE OF RADIATION Earth and sun separated by vacuum. Heat from sun is transferred To earth by radiation without the need of medium

ABSORPTION

AND

RADIATION

All materials can absorb and radiate DEPENDS ON: 1. surrounding temperature ~ object that has higher temperature than its surrounding, radiates heat ~ object that has lower temperature than its surrounding, absorbs heat 2. nature of its surface ~ dark and dull – best for absorbing heat ~ bright and shiny – best for reflecting heat NATURE OF SURFACE HEAT ABSORPTION

HEAT RADIATION

DULL

GOOD

GOOD

SHINY

BAD

BAD

BRIGHT

BAD

BAD

DARK

GOOD

GOOD