114998994 physics spm paper 2 tips 89 modification and 11 decision making question and answer

MODIFICATION-SECTION B

CHAPTER 11. Suitable ruler to use in laboratory Suggestion Explanation

Smallest size scale 0.1 cm More accurate

High accuracyLess error in measurement

High consistencyLow relative deviations

Plastic material Avoid parallax error

Thin thicknessAvoid parallax error

CHAPTER 2

2. Explain the suitability feature of arm exercise equipment.

SuggestionExplanation

Spring made of steelCan withstand higher force

Two // more spring arrange in parallelThe spring system is stiffer

Spring with ticker wireWire will not easily break

Smaller diameter coil of springThe smaller the diameter coil less elastic the spring, so the arm exercise would not so hard

Choose large force constant springWill make strong spring, the spring will stiffer and not broken easily

suggestionExplanation

Use tight and light suit Less air fraction

Use spikes shoes Better grip support while running and prevent slippery

Use thicker mattressIncrease time impact , reduce impulsive force . prevent back injury

The athlete have to sprint before jumpCan increase kinetic energy

Athlete have to bend the body during fall Increase the time impact , reduce impulsive force

3. Suggest the suitable cloth , equipment and techniques to improve high jumper athlete and their safety .

4. Explain the characteristic of spring to make babys cradle.


Choose large force constant springWill make strong spring, the spring will stiffer and not broken easily.

Choose large diameter of wireThe larger diameter the stiffer the spring is.

Large diameter coil of springThe larger the diameter coil more elastic the spring is

The spring is made of steel or alloySteel and alloy is stiffer than iron

The arrangement of spring is two or more line in parallelThe spring is stiffer

5. Explain the most suitable design of spring for shock absorber for motorcycles.


Small diameter of spring coilEnough space for the spring

Choose large diameter of wireThe larger the diameter the stiffer the spring

Force constant is more than 1000NCan support motorcyclist and passenger up to 100kg

Higher spring constantSmall compression of the spring

Small natural frequencyTo reduce bumping, comfortable for user

6. Explain the simple characteristic of the rocket than can travel with greater acceleration.SuggestionsExplanations

Choose metal with high strength and hardnessEven under pressure the shape will not change easily

Frame of rocket is made of low density metalLighter, can increase acceleration

Multistage rocket inventedEach stage has burning fuel, pump and combustion chamber. It will slip off when fuel of each chamber completely burn. When the mass decreases, the acceleration increase

Rocket need to carry a tank of oxygenTo enable the combustion of fuel in space

Silver color rocketReflect light efficiently so the temperature of the rocket will not rise

Cover the body of rocket with heat insulatorFriction between air and body will increase heat. The insulator will reduce heat conductivity

Aerodynamic shapeReduce air friction, move faster

7. Suggest and explain the build of water bottle rocket in school competition to move higher altitude and has longer time on the air.

SuggestionsExplanations

The body of rocket must be toughDo not break easily in high pressure and when landing

Smaller massRocket will accelerate faster

The shape is streamline/aerodynamicReduce air resistance

Nose cone or bullet shape on top of bodyTo improve the aerodynamic of rocket

45 angle of launchingThe rocket can travel maximum distance

The volume of water is half or 1/3 from the whole volumeTo increase momentum and impulsive force

Attach 3 or 4 fins at the tail of rocket space equallyRocket will move smooth and stable

Attach parachutewill make the rocket floating and has longer time on the air before landing//decrease the speed of falling due to air resistance

8. Give suggestion to improve the design of jet engine so that it can be use for larger airplane at the higher speed.


Increase more fuel injectorsMore fuel to be burnt to produce greater force

Increase the size of the combustion chamberMore space for fuel to burnt

Decrease the diameter of the nozzleExhaust gas ejected at higher velocity

Increase the speed of blade/use bigger bladeIncrease the air intake

Blade and engine made of strong materialsCan withstand strong pressure and wont break easily

9. Base on the physic principle, suggest the design of roller skate track so it can be use to oscillate skate continuously.


Semi circular curve shapeExchange between kinetic energy and gravitational potential easily

Smooth surfaceReduce frictional force/easy to slide

The slope slightly increase and decreaseEasy to oscillates cause by changing of energy

Use strong material such concrete of foundation of the trackWithstand high impact such as high force of jumping and landing

Soft layer at the surfaceReduce impulsive force when landing, low risk if accident

10. Explain the most suitable design of motorcycle that can move fast, safe and save time in racing.


Lower seat heightLower center of gravity or more stable or safer to turn.

Bigger width of tireBigger surface area, better support or low pressure acts on the tires or more friction when breaks.

Less thread patternTo decrease friction of tires to the road, can move fast

Smaller massLighter, can move faster or low inertia

With ABSMotorcycle does not stop immediately or can be controlled if direction changes or does not move sideways or more friction with ABS

11. Suggest and explain how to make suitable beach motorcycle which able to move on the sand smoothly and comfortable.


Deep thread patter // more definitive patternBetter grip on sand, able to move smoothly on sand

Large tire (big surface contact with ground)Reduce total pressure of car, increase stability and the car would not get stuck in the sand

Soft seat and water resistanceComfortable for cycles and would not get wet easily

Excellent resistance to rustingEverlasting. Would not rust easily

Attach shock absorber with higher spring constant and small natural frequency.Reduce bumping, comfortable to cycle with

Low density bodyLighter, would not stuck in sand

12. Suggest the suitable cloth and the best techniques to catch ball to prevent injury for goalkeeper.

SuggestionExplanations

Wear glove Reduce painful of the players hands when touching the ball with big impulsive force.

Use soft material for glove Lengthen the time impact, reduce impulsive force.

Wear cloth which is made from material with moderate specific heat capacityThe cloth can absorb more heat when the player is sweating to maintain the temperature of player.

Base of shoes has studPlayer give great pressure to make stud sink into ground and give stronger support without slipping.

When catching the ball, the goal keeper should move his hand backwards This action lengthen the time impact between ball and hand, so it reduce the impulsive force.

The ball should have enough air pressure inside Shorter the time impact between foot and ball, so impulsive force increase then the ball will has high speed and travel far away.

13. Using physics concept, suggest and explain suitable athletes attires, running, jumping, landing techniques and other aspects to help the long jumper can jump further.


Use tight and light suit Less air friction

Use spike shoesBetter grip support while running and prevent slippery

The athlete have to sprint before jump Can increase the kinetic energy//momentum

The athlete have to push the body infront while jumping Increase the elastic potential energy//able to increase longer distance of jumping

Athlete have to bent the body during fallIncrease the time impact, reduce impulsive force, less injured

14. Safety feature in car

CharacteristicExplanation

The bumper of car is prone to crashIt will increase the time impact, the impulsive force will reduce

The sitting space of the passenger is reinforcedTo protect the passenger

Use safety beltDuring collision, safety belt will hold the passengers from thrown infront due to inertia

Use air bagWill inflate when accident occurs, the driver safe from hitting steering

Antilock breaking system(ABS)Allow car to stop quickly on slippery road and prevent from skidding

Strong steel struts Give good protection from side on collision

Tire with treadCan stays contact with road, prever slippery

15. Explain the suitable loaded lorry which can carry liquid, such as petrol


The load of lorry should be divided into many smaller tankTo reduce effect of inertia

The load must be tied So it will no fall of from the lorry

Far gap distances between tractor and trailerPrevent collision between tractor and trailer, easier when turning

Use more tire for lorryPressure will be separate to all tires, able to carry more loads. Lower pressure better support and stability

Small belt behind lorryTo discharge spark, safety reason to prevent from burning the petrol

Use antilock break system (ABS) The lorry can stop easily without skidding

16. Explain the design of and how kayak which can travel faster and safer.


Streamline /aerodynamic shape of bodyReduce water resistance

Smooth surface body /coated with waxReduce friction of body towards water

Low density materialLighter , easier to float, easy to carry and sail faster

Strong material body and peddle Everlasting , not easily broken

Wider peddle surfaceGreater force because more water are peddled up

Wear safety jacketPassenger can float and safe if they fall into water.

17. Give suggestion to design a sail boat which can travel faster and smooth.


Streamline /aerodynamic shape of boardReduce water and air resistance,can increase lifting

Smooth surface board/coated with waxReduce friction toward water

Low density materialLighter, easier to float and sail faster

Strong materialWithstand strong wind, not easily damage

Wider sailGreater lifting force because more wind are captured

18. Modified the ship that can carry more and heavier load, move faster and safe while travelling.


Strong materialCan withstand great force

Low density materialLight weight

Has more than two stage,plimsoll lineSafe to travel on the fresh and salt water

Big sizeCan place more goods

Aerodynamic/streamline shapeReduce water friction.

Waterproof sailSail would not get e=wet easily.

19. Suggest how to increase the safety for motorbike racer to reduce injuries / accident


Use helmetTo protect the head

Use helmet with hard outer casing and soft inner linerHelmet reduce head injuries in a crash by spreading the impact with hard outer casing and absorb energy with soft inner linear of styrofoam

Use safety jacketTo protect the from injuries , cut ,burn

Use glovesTo protect the hand

Use padded leathers suitWill soften any impact and protect the skin from abrasion

20. An earth-monitoring satellite falls into the earths atmosphere at a high velocity and reaches a high temperature. This is caused by the earths gravitational force and air resistance.Using the appropriate physics concepts, suggest and explain suitable designs or ways to protect the satellite and its equipment:SuggestionExplanation

Aerodynamic shapeTo reduce air resistance

Heat shield / material that is hard to burnTo protect the capsule

High melting point //ceramicDo not melt

Landing in water // air bag Increase time of impact// Reduce impulsive force

Light material / / small mass // low density-Reduce the inertia // -reduce the momentum //-reduce impuls

Paracute / /Retro rocket To reduce speed

Hard material // stiff compositeNot easy to bend

21. Explain how you would design the pile driving system.[the ram hammer is lifted to a height by the crane and allowed to fall on the pile.ModificationReason

Large hammer weightLarge momentum when it hit the pile

Ram hammer made from hard material such as alloysNot break easily/last longer

Hammer raised at higher positionInrease the gravitational potential energy

Stronger End of the top of the concrete pile To avoid break at the top couse by the hammer

Sharp End of the bottom of the concrete pileTo increase the pressure

CHAPTER 3

22. Efficient brake system SuggestionsExplanations

Type of liquid: oilUncompressible

Thickness of brake line :highTo counter the high pressure from the liquid

The ratio of cross sectional area for wheel piston and master piston :highTo produce larger force on wheel piston

The chosen of type of brake for front rear wheel:

Front wheel - disc

Rear wheel - drumDisc brake is more efficient than drum brake

23. Explain the design of hydrometer which can be use to determine a wide range of densities of liquid.


Small stem and longIncrease sensitivity where the scale division are far apart so that small changes in density can be detected

Glass wallDo not erode and small adhesive force

Large diameter of bulbHigh up thrust / displaces more liquid / able to float easily

Scale can be made bigger or smaller than the density of water.[calibration] The hydrometer is floated in alcohol. The liquid level at the stem is marked (upper level)

Then, the hydrometer is floated in higher density liquid like mercury and marked (lower level)Ability to measure a wide range of densities of liquids.

Lead shotsHydrometer can stay upright

24. Describe the suitable design to build mobile tent for Sure Heboh event which will be construct at open space for a week. Using appropriate physics concept, suggests and explain.


Choose low density metal for frameLight weight and strong

Use hollow rod which can assemble easilyHollow rod is not heavy, but equally strong, easy to mobile anywhere, faster to build, can reduce the cost of construction and transport

Water proof canvasIf raining, would not getting wet

Anti rust rodCan withstand rain and long lasting

Sharp end rodSmall surface area, so higher pressure to ground, yet the tent can be planted into ground firmly and stand still

25. Explain the necessary modification for the structure of dentist chair for children that are suitable and save for the adult.


Increase the cross-sectional area of big piston and decrease the cross-sectional area of small pistonTo increase the output force acting on big piston / to lift havier adult / to increase force multiplier of system

The wall of pipe is made up of strong alloy to hold the fluidTo withstand the strong pressure that might cause cracking in the channel

Change the less control into electric touch controlTo lift or lowered the chair to the desire weight more easily and safety

The surface area of the seat enlargedTo support the people with the large bodies

Use non-corrosive oil in jackSo that the wall of the pipe will not be controlled and cause leakage

26. Explain the build and design of hot air ballon wich can fly higher altitude faster and suggest some safety aspect.


Large ballonProduce bigger buoyant / upthrust force, increase the volume of air displacement

Many hot air burnerHeat up the gas inside faster

Synthetic nylon ballonAir proof, light weight and strong material

Gas temperature is highReduce the density of air in ballon

Total of mass is lowBallon move upward faster

Rattan basketLonger the time impact, reduce the impulsive force to passanger when landing

Fly on early morning or late afternoonThe temperature outside the ballon is cooler compare to the inside of ballon, so the ballon will rise higher

27. Explain the basic structure of small submarine that can be use for underwater exploration.SuggestionExplanation

Strong materialDoes not break easily

Aerodynamic shapeReduce water resistance

Thick wallWater pressure increase with depth

High density materialsIncrease mass / can submerge easily

Ballast tankTo increase or reduce weight

Sonar transmitter and receiverTo estimate and depth

28. Suggest the design of submarine which can submerge and float in the sea.


Ballast tank are partially filled with waterThe submarine will partially float

Aerodynamic // streamline bodyTo reduce water resistance

Use hard and stiff materials for bodyTo overcome the pressure of water in the sea

Attach periscopeTo view surrounding area when submarine float

Use nuclear power sources to generate powerCheap and lasting power

29. Explain the characteristic of material to be use for making the sole of jungle trekking shoes.


Rubber soleGood impact absorber

Low densityLight weight

Many studGive extra grip

Low expansion effectNot loose easily

Excellent ability of stretchComfortable to feet, foot can move unstressed

30. Using physics concept, explain necessary deep sea diving suit and other accessory to carry.


Choose strong helmet with thick metal and glass to cover headTo withstand high pressure of water and protect the head

Use thick glass in front of diver faceEnable the diver to see surrounding and at the same time able to withstand the pressureof water

Use water proof suit and able to withstand pressureDue to depth, the pressure under water is very high

Bring along gas containing mixture of oxygenTo provide oxygen to diver for breath

Use very heavy suit The diver enable to stand on the floor of ocean and able to fight buoyancy of water

31. Modified the passanger airplane to cargo airplane that needs to carry more laod, less use of fuel, effenciency and safety to travel.


Increase the size of the bodyTo increase the space

Increase the length of the wingTo increase the upthrust

Increase the thickness of the bodyTo stand higher pressure difference

Use a more powerful engineTo overcome bigger inertia and do more work per unit time

Increase the number of tyresTo support higher mass or pressure while landing

Protective bar between the cabin and the pilotTo prevent moving object to knock at the pilot while landing

Pilot has ejected seat during emergencyTo save the pilot if plane crash happened

32. Design Vacuum CleanerSuggestionExplanation

Large fan drivenInrease the spped and amaunt of airflows

Powerfull of lectric motorInrease the spped and amaunt of airflows

Narrower inlet openingInrease the velocity/decrease air pressure

Using a very large filter to block dust particles while allowing air moleculs to pass throughTo have a lots of surface area and many pores for air to flow through

Larger spaced for depositing and collecting the dust particlesEnsure that the air flows through the filter is not block by too many dust particles

33. Design paint sprayer


Large size of air vesselCompress more air/can exert large pressure

Rubber material for the vesselMore elastic/easier to squeeze

Narrow shape of the tubeAir can move with high speed

Fibre glass material for the rodStronger and last longer

Size of nozzle is narrow at the endThe paint can be sprayed evenly

34. Design hidraulic jack


Bigger crossectional area of slave piston(big piston)Produced higher force

Small crossectional area of master piston(small piston)Less forced is needed/produced bigger pressurre

Longer handleLess forced is needed to press small piston(master piston)

Low density of a bodyLighter

Oil for liquidNon-compressable

Release valve between small and main reservoir(reset)Liquid can flows into small reservoir easily when push the reset button.

35. Design hydrometer


Bulb with lead shot at the lower sectionTo submerge the hydrometer and not overturn

Cylinder with bigger diameter at the bottomnot overturn/increase stability

Cylinder with smaller diameter at the upper sectionA small reading scale can be incorporated/inrease the sensitivity

Smaller scaleinrease the sensitivity

Filled with airInrease the beyoncy force

Glass wallNot corrode easily

CHAPTER 4

36. Most suitable design of thermometer to use in Antarctica


Use alcohol as liquid in glass thermometerFreezing point of alcohol is -115oC .So , it will not freeze at low temperature

Use thin wall of bulbSo it will sensitive to the change of heat

Use small diameter of capillary tubeAlcohol can expand at high rate for the small change in temperature

Use thick glass wallThe loss of heat to surrounding is small

Use round glass stemCan act as magnifying glass , so the alcohol level can be seen clearer

37. Most suitable design of clinical thermometer


Use mercuryEasy to read because it colour and opaque

The scale range from 35oC to 42oCTo measure human body heat

Small diameter of capillary tube// extra fine bore tubeMercury can expand at high rate for a small change in temperature

Use thin glass wall of bulbSensitive to change of temperature

Use round glass stem and wallCan act as ,magnifying glass. So, mercury can be seen clearly

38. Explain the design and the characteristics of the cooking panSuggestionExplanation

Base is made of a copperCopper has a lower heat capacity it become hot very quickly

High density of baseHeavier base make the pot stable and not topple over easily

Body is made of aluminiumLow specific heat capacity becomes hot very quickly but it low density make it overall weight of weight lighter

Handle is made of wood or plasticHigh specific heat capacity so the handle do not become hot . Safe

Choose low density material for handleDoes not add much to the total weight of pot

Transparent pot coverAble to cooker to see the food. Food cover will trap the heat

39. Suggest and explian the design of water heater to boil a large quantity of water faster ,efficient and safely


Use tungstenHigh melting point,high heat energy

CoiledLonger wire,increase the resistance

High melting pointNot easy to melt at high temperature

Lower rate of rustingDoes not get rust easily

Use thermostatWhen temperatures reach 100 Celsius, the water heater will automatically turn off

40. Determine the modification to be made for container,so the cut fruit will keep cool, remain fresh and easily seen by customers.


Use container with high specific heat capacityAble to slow down the loss of heat from the container

Place small ice packet below the bottom of the cut friutsThe cut fruits is chill and juicy, ice able to absorb a large amount of latent heat when melt

Add salt to the packet of iceForeign matter will increase the freezing point of ice, so this will slow down the ice from melting

White wall colour of containerCan avoid absorbtion of heat from the surrounding

The container has double wallAvoid heat from surrounding transferred easily to container. The inside container remains cool

Transparent wall of container in front of customerThe customer can see and choose the cut fruits easily

41. Investigate the most suitable liquid that can be use as coolant for car engine using physics concept.


Low freezing point liquidWill not freeze easily during winter weather

High boiling point liquidDo not easily boil when absorbing heat from the engine

High specific heat capacity liquidCan transfer large contain of heat with a small rise in temperature. Able to cool up the engine

Low ability to react with metalThe metal part of the engine will not corrode easily

42. Most suitable thermometer for laboratory to measure the temperature of ice and boiling point of water


Size of the bulb is smallDoes not need a lot of heat to heat up the mercury to expand

Use thin wall of bulbSo it is sensitive to change of heat

Use mercury Freeezing point of the mercury is -39 degree celsius and boling point 357 degree celsius . Able to has a range from -10 to 110 degree Celsius. Mercury can expand a high rate for small change of temperature

Use thin wall capillaryAble quick heat transfer from the surrounding to the mercury. So, the thermemeter is more sensitive

Has minimum size scale with small divisionMaking thermometer a sensitive instrument

43. Modified and explain the design of an efficient solar water-heating system on the roof.


Pipe embedded in plate must be longLonger pipe will has greater surface area which can absorb heat faster

Use metal pipe as pipe inside the plateMetal is good heat conductor , so heat will easily transmit to water

Use insulator behind the absorber panelInsulator will prevent the heat loss

Use black absorber panelBlack is good heat absorber

Cover the top of the panel with glassHeat will trap inside due to green house effect

Put the tank at higher levelTo give higher pressure

44. Explain the build of solar cooker oven that been use in science month competition at your school to boil 500ml water in short time.


Build the solar cooker with shiny// silver colour reflector insideThe light will reflect to the cooker and heat up the water

Use metal cookerGood conductor

Paint the outside part of the solar cooker and the cooker ( contain water ) with black colourTo absorb

Wrap the cooker with plastic or glassAvoid heat from release to sorrounding

To trap heat, the temperataure will increaseTo absorb heat, the water boil faster

45. Suggest the design of heating system in the house and characteristics of heating agent. The house use central heating system with boiler, radiator and pipelines.


Use strong materialNot easily break

Use metal pipe with good heat conductorIncrease the rate of heat transfer

Increase length of cooling coilCan transfer the heat faster to surrounding

Use greater boiling point liquidLiquid not easily change into vapour

Low rate of rusting materialLong lasting, not easily rust

The bigger size of radiator fanCan blow and cool down larger area

Pipe in coil structure is usedIncrease the time of floe and increase the quantity of haet transferred.

46. Suggest the characteristic of material to build food container which can keep the food warm.


Food container should made of low density materialLighter , the container able to be move from one place to another.

Melting point of container should be high To prevent the container from melting up when hot food is store inside

Specific heat capacity should be highSo the container will not get hot easily. Safe to touch and handle.

Thermal conductivity is low.iGood heat insulator , to ensure the heat not loss and the food remain hot.

Double wallTo prevent hest loss.

47. Explain the characteristic and design of thermos flasks to maintain hot water.


Use hollow plastic stopperAble to trap air as air is poor heat conductor.so,less heat loss through stopper.

Vacuum spacePrevent heat loss through conduction or convection

Has double wallHas vacuum in between heat not easier pass through the wall of thermos.

Double walled tube coated with shiny paintShiny surface reflect heat from the wall of thermos flasks back to water.so the water remain hot.

Double walled made of glassGlass is bad conductor.it will reduce heat loss.

48. Explain how the design of radiator of the car and characteristic of cooling agent which can absorb heat at short time,


Increase the length/area of cooling coilCan transfer the heat faster to the surrounding

Increase the number of fin bladesCan cool down faster

Use larger fanCan cool down larger area

Use cooling agent liquid with greater boiling pointIt wont boild easily in high temperature

Use cooling agent liquid with higher specific heat capacityAble to absorb large amount of heat

CHAPTER 5

49. Determine and explain in the build of magnifying glass to be use for enlarging the image of stamp


Choose convex lensThe image will magnify

Excellent clarity of lensThe image is clearer

Small focal lengthAble to focus nearer

Medium diameter of lensAble to be hold by hand to identify the stamps

The object is place less distance than focal lengthThe image form is magnify, virtual and upright

50. Explain the suitability of the mirror that be use in shop to watch over the customer


Use convex mirrorWider field of view

Greater reflectivity of materialClearer image

Choose a bigger size of mirrorEnable wider view and sharper image

Place the mirror at the corner of shop ceilingEasier to look at and wont disturb the customer pathway

Low densityLighter to hang up

51. Design fibre optic


Use refractive index of outer layer is less than the refractive index of inner layerSo that total internal reflection can happen in the fiber optic.

Use high flexibility materialso that it can be bend easily

Use strong materialdo not break easily

Use thin materialLighter // can be use in small area

Low density materialLighter

52. Determine and explain the build of microscope using lens P and Q with focal length of 15 cm and 5 cm respectively. Suggest modification that need to be done to get brighter ang bigger image.

SuggestionExplaination

P as eye piece and Q as objective lensFocal length of P is longer than Q

Fo < u fo + feTo produce bigger image from the eyepiece // to increase the magnification

Store in a cool and dry placeTo avoid formation fungus at the lenses

Use more powerful// shorter focal length lensesTo produce bigger image

Use a lamp near the object// use bigger diameter of objective lensTo produce brighter image

53. Explain the suitable characteristic of the mirror to be use as outdoor safety mirror at the corner of the road


Use convex mirrorWider field of view

Excellent weather resistanceAble to withstand bad weather

Excellent impact resistance of materialSave cost, everlasting

Bigger size mirrorTo enable a wider view and sharper image

Greater reflectivity of materialClearer image even in bad weather

Place at the sharp road corner , at bending roadTo minimize from accident occur, to enable motorist see the oncoming traffic

Small roofProtect from rain drop for better image

54. Detemine and explain the build of Astro disc using appropriate physics concepts.


Choose convex curve parabolicThe signals come can be focus at one point

All signal are focus on focal pointBetter reception

Smooth surface of discBetter reflection

Locate the disc at high and facing towards satelliteNo obstacle, better signal

Clean surface of disc, no water drop or dirtBetter reflection, almost 100% reception receive by feed horn

55. Modified the slide projector that need to be place in school hall and can be seen by many student with clearer image.

suggestionExplaination

Use higher power bulbHigher intensity of light or more light produced

The filament of the bulb is at the focus point of the concave mirrorThe light focuses at one point. // parallel ray can be obtained after reflection by concave mirror

More curvatureMore light to be reflected (upward) // less light toward other direction other than upward

Lens between f and 2fTo produce real ang enlarge or bigger images

Increase the distance or further away the screen Larger image produced

Electric fan operates during and after the lamp is switches onCooling system to stabilized the temperature (heat energy produced by filament bulb) to increase the projector lifetime

Use condenser mirrorTo concentrate more light to the slide

Use a concave mirror instead of plane mirrorFocus the light directly to the lens // increase the intensity og light

Place the filament at centre of curvature of the converging mirror // use high powered lensLight goes directly from the lamp and reflect back on the same path // increase the intensity of light toward the transparency // to get brighter image

Use heat filterTo absorb excess heat to the transparency

56. Determine and explain the build of telescope using lens J and K with lens K is thicker than lens J which produce bigger and clearer image.

Suggestion Expalanation

C hoose lens K as eyepiece lens

Lens K is thicker than lens J Light ray is refracted more in lens K than lens J, focal length of lens K is shorter than lens J

Therefore the thickerthe lens, the greater the refraction of light and with that the shorter the focal length of a lens will be

Choose lens J as objective lens

Use bigger diameter lens as objective lensCharacteristics of objective lens for telescope is

Has larger surface area which allow more light enter

Has a longer focal length

Use low power convex lens as the objective lens Magnification of telescope =f0/fe

Low power lens has a longer focal length ,fo higher, magnification higher

Use high power convex lens as the eye lensHigh power lens has a shorter focal length,fe higher, magnnification higher

Use bigger diameter of objective lensMore light permitted to enter the telescope and a clearer image is seen

CHAPTER 6

57. Design a good beach


near the baydivergence of the waves energy /calmer

High retaining wallsOver flow

To reflect the waves from the shore

Reduce direct impact of the waves on the shore

Wall from concretereduce erosion are built

Concrete barrier structure with a gapWaves passing through the gap will be diffracted in the childrens area.

-reduce amplitude

Tambak laut supaya lebih cetekReduce speed

More number of treeDiffraction occur will reduce tha amplitude

Uneven surface of retaining wallReduce energy

58. Suggest and explain how ordinary fishing boat can be upgrade to the new boat which complete equipment to detect the crowd of fish.


Attach radar system to the ship

a) Ultrasonic transmitterThis equipment needs to detect crowd of fish and for measurement the depth of the crowd of fish

-Use to produce ultrasonic pulses

a) Microfone recieverTo detect ultrasonic pulses

b) CRO-To measure the depth of fish by calculating d=vt/2; d=depth, v=velocity, t=time

Use ultrasonic wave-Ultrasound not produce sound

-Ultrasonic wave has higher frequency, more energy, so it can move further

Use high energy waveThe penetrating power is higher

59. Explain the suitable design or method to build quality concert hall.


Cover the hard wall with soft board or thick curtain Soft surface can absorb sound and reduce reflection of sound

Place the wall with hole or egg carton design Can reduce reflection of sound so sound will be clearer/reduce echo

Fixed 2 loud speaker in concert hallLoud speaker can act as coherent sources for constructive inteference

Arranged the sit at antinodal place Strong sound can be heard

Use glass or mirror hall which is the type which are not easily brokenSound with high frequency might break the glass

Use special computer to generate sound wave which produce destructive inteferenceAudience can enjoy better presentation without disturbance

60. Explain the suitable design of retaining wall to protect the ship at the harbor

SuggestionExplaination

Build concrete retaining wallCan withstand impact of the wave, difficult to crack

Retaining wall should be curved and uneven surfacePrevent reflection of wave back to the ship

Build retaining wall in front of the bayThe wave are calmer at thr region

Retaining wall has gapDiffraction will occur

The gap at retaining wall is narrow( smaller than wave length)The greater the curvature of wavefront will occur. Amplitude after passing gap is smaller

There are slope at the bottom of retaining wallAt shallow region, the wavelength of wave is smaller, so the velocity of the wave smaller

Retaining wall should be build higherTo ensure no spill over of wave

Build the jetty at bayThe wave at bay is calmer

61. Explain the characteristics of parabolic radar system to detect signal from satellite communication.


Large diameter size of parabolic discAble to receives more electric signal

Type of wave transmited is MicrowaveHas high frequency, high energy, short wavelength so it is easy to be reflected

The distance of the signal receiver from the centre of parabolic disc is the same as the focal lengthThe signal can be focus to the centre of the parabolic disc

Place parabolic disc higher from the groundThe signal with not be block by trees or anything and the signal easy to be detected

Place parabolic disc at clearplaceNo signal disturbance

CHAPTER 7

62. Suggest the suitable lamp that can be use in the library, cheaper yet become the room brighter


Lamp with parallel circuitIf any lamp were burn out, others can still be used

Attach shiny reflectorCan reflect light more, no need to install more lamp, the room will become brighter.

Low power lampSafe cost

High efficiency lamp // fluorescentThe room looks brighter

Long life span lampNo need to replace often

Low price lampSave money

63. Explain the modification of menthol bulb lamp to efficient lamp to be use in study room.


Use the fluorescent lamp not a filament bulbFluorescent lamp use less power and economic (consume less power) compare to filament bulb.

Bigger cover with white colourLess reflection on eyes and absorb less heat energy and good heat reflector

Use the adjustable stand or portableThe height of the lamp can be adjusted can be used anywhere

Connect with the earth wireAvoid short circuit and damage on the bulb

Use an energy saver lampProduce same brightness with less power consumption

64. Suggest the suitable design of fuse to protect an electrical equipment which is label 240V,2400W


Thin fuse wireLess space/to carry a limited electrical current/less mass hence low heat capacity/shorter time to heat up to melting point and blow

Ceramic cartridgeCan withstand higher temperature because spark created by high voltage.240V can be huge

Fuse rating is 13AMaximum rating must be sligthly higher than normal current

Low melting pointFor fast blow/melting faster when excessive current flow/easy to cut the current flow

Low specific heat capacity The fuse wire easily heated,melt and break the circuit

Metal is usedGood electric conductor

Resistance to oxidationDoes not interface with other function

65. You have to choose one of the cables to be used in the National Grid Network. Explain the suitability of each of the characteristics of the cables.


Diameter should be largeTo reduce the resistance of the cable

density should be lowThe cables will be lighter and can be supportedsecurely

The rate of expansion should be lowSo thre is less expansion and less sagging in the cables during hot days

The melting point should be highSo the cables does not melt in high temperature

66. Explain the characteristic of electric pylon and the cable taht been use for electric transmission


Material: steel alloyStrong,will not break easily

V shape steel alloyNot too heavy

Trust and supprt joinCan support bigger weight

Made from small diameter and laminated wire Reduce addy current

Cable made from low density materialCable is not heavy/ light weight

67. Investigate the characteristic of electric oven that can toast more cupcakes at less time


The space inside oven is build biggerIt can fil up 180 slices of bread

Increase the number of resistance heater at the top and bottomSo it can supply enough heat

The wall is made of good insulatorTyhe heat will not lost to surrounding

Fix a fan inside the ovenHeat energy releaswed can spread uniformly in oven

Internal space of oven is painted silverSo the heat will radiated at wall and reflected back completely

Fix the step up transformerOven can receive higher voltage and can function with higher power

68. Explain the designof electric kettle


Material of heating is made from nichromeTo produces high heat energy

High number of loopTo increase surface area so that more heat is released

Use high powerTo produce more heat energy in the coil

High melting point coilNit easy melt under high temperature

Low rate of rustingDoes not get rust easily

Use thermostatWhen temperatures reach 100oC

3 plug in

If short circuit the overload current flows to earth(for safety reason)

69. Design incubator used to hatch eggs


Parallel circuitWhen one bulb damage the another bulb still function/heat can distributed uniformly

Multi storey rackMore eggs can be arranged

Using fanheat can distributed uniformly

Bulb with same brigthness and powerheat can distributed uniformly

Using alarmTo ensure that correct timing is employed in the hatching of eggs

70. Design circuit for cabin or house


connected in parallel Allow each electric appliances to be switched on and off independently

Fit fuse at the live wire in the fuse box To stop the flow of current by melting when a high voltage of electric current flows through the circuit // switches itself off very quickly if the current exceeds e.g. 15A (for 15A mcb)

Earth connection to the metal case of electrical appliancesEarth wire connected to earth, so that when a fault occurs and a current flows through the live wire and the earth wire, the fuse in the live wire will blow and cut off the supply. It will protect a person who may touch a faulty or live appliance

Use low power lamps / install fluorescent lampTo save the energy

Regularly cleaning and removing dust from the air filters of air conditioners// Do not put more water in a kettle than needed for hot drinksTo save the energy

CHAPTER 8

71. Suggest modification that need to be done on dc motor to increase efficiency of the motor.


Low density materialCoil hass smaller mass/ lighter

Increase the number of turns in the coilCan increase magnitude of force/ higher electromagnetic field strength

Use high strength of magnets/ Add more magnetsIncrease the strength of magnetic field

More segmentsCoil rotates smoothly

Increase the magnitude of currentCan increase the magnitude of force/ can increase the strength of magnetic field

72. Investigate the design and the characteristic to improve the efficiency of transformer.


Use soft iron coreEasy to magnetized and demagnetized

Laminated coreLess eddy current or reduce energy lost

Use thick wireReduce the resistance or more current flow

Use copper wire to make coilLow resistance or reduce the lost of heat

Wind the secondary coil on top of the primary coilReduce leakage of field lines

73. How to design a moving coil ammeter that can function better and able to detect small change of current?


Use stronger magnetStrong magnetic field or larger rotation

Use curve magnet or concave Produce radial magnetic field/to get linear scale

Use cylindrical coreTo supply uniform magnetic field

Use soft iron coreTo concentrate the magnetic field

Use linear scaleThe angle of rotation is linear

The sensitivity of moving coil galvanometer can be increased by increasing the strength of the radial magnetic fieldIncrease the force between the current carrying coil and magnetic field

Using hairspring of lower stiffnessSmaller opposing force to stop turning of coil

Use lighter pointerSmaller inertia easier to move

Use a coil of a lighter massSmaller inertia able to move easily

Increase the area of coilMore changes of magnetic flux,a bigger force are produce

74. Suggest and explain the build of adaptor to charge the 8V handphone from 240V power supply.SuggestionExplanation

Use step down transformerAble to reduce voltage

Ratio of turns 30 : 1 // 240V:8VCan reduce voltage from 240V to 8V

Use four diodesFull wave rectification

Full wave rectifierTo convert au current to dc current

Using a capacitorTo smooth output current (steady direct current

CHAPTER 9

75. Suggest and explain the build of adaptor to charge the 8V handphone from 240V power supply


Use step down transformerAble to reduce voltage

Ratio of turns 30 : 1 // 240V:8VCan reduce voltage from 240V to 8V

Use four diodesFull wave rectification

Full wave rectifierTo convert au current to dc current

Using a capacitorTo smooth output current (steady direct current

76. Consult and modified the automatic switch light (diagram A) above which can switch on at night and switch off during morning to be automatic switch on fire alarm when there are fire , explain using diagram and the function of component.


Change R1 to termistorThermistor can be detect heat from fire

Change LED with alarm// sirenAble to produce sound of alarm if fire is detected

Change LDR with R1During fire, R1 has greater resistance compare to LDR so, no current flow

When the temperature is high, the resistance of thermistor is low. This will increase the voltage acroos R1. So, currnt will flow to the base of transistor , than the transistor is switch on followed by greater increase in collecter current. The alarm will switch on.

77. Suggest the modification need to be done to the circuit in Diagram C so that it can function as automatically fire alarm switch that need high voltage.

Suggestion Explanation

Replace LDR with thermistorTo detect heat when temperature is high

Replace bulb with siren/bellTo produce sound

Connect relay switch to output transistorTo switch on the siren

Interchange the position of resistor R and thermistorTo increase base voltage//voltage across R//base current

Use 240 V power supplySiren is function as high voltage

78. Modified the circuit 240V and Np = 4000 turns circuit to switch on 12V d.c radio.


Step-down transformerCapable of reducing potential difference / voltage

Ratio of turns 20 :1 // 240:12 Np = 4000 turns and Ns = 200 turnsReduce potential difference 240V to 12V

Using four diodesFull wave retification

Using a capacitorTo smooth out output current // produce output to steady direct current.

79. Moving coil microphoneSuggestionExplanation

use thin diaphragmEasy to vibrate

Use strong materialNot easy to break

More number of turns of coilIncrease the rate of change of magnetic flux linkage // The magnitude of the induced current or is also increased

Thicker diameter of wire of coilreduce the resistance of the coil

Using more powerful magnetto increase the strength of the magnetic field.//Increase the rate of change of magnetic flux linkage//The magnitude of the induced current or induced electromotive force is also increased

CHAPTER 10

80. Explain the suitability of characteristic of radioisotopes to be used as treatment in brain tumor radiotherapy?


Short half lifeRadioactive is dangerous substance, short half lfe can decay faster

Gamma ray radiationGamma can kill cancerous cell and can penetrate skin of patient

Low ionozing powerMinimum damage to tissue organ

Liquid state of matterEasy to dissolve

High penetrating powerCan penetrate easily

81. Suggest and explain the safety ways, which are required when handling radioactive substance.


Use thick lead boxRadioactive rays evem gamma cannot pass through

Use forceps / robotic handAvoid direct touch

Wear photographic filmAble to detect exposure radiations

Wear plumbum safety suitTo protect the body from expose to radiation

Use sirenFaster warning when leakage

Packed into concrete drum and buried undergroundPrevent the radioactive waste discharge to environment

Always place GM detector nearbyTo detect the amount of radioactive nearby, for safety

Label the radioactive container with symbolEasy to detect radioactive substance

82. Explain the suitability of characteristic odf radioisotope to be use in controliing the population of pest


Use gamma rayAble to mutate the insect

Solid state of matterEasy to handle

Long half lifeLast longer

High penetrating powerAble to penetrate thick object/material

High ionizing powerAble to change// mutate the biology of insect

83. . Explain the suitability of characterisitc of radioisotopes to be used in th trace of water pipeline.SuggestionExplanation

Short lhalf lifeRadioactive is dangerous substance, short half life can decay faster

Few hour half life Enough time for worker to detect the pipe leakage

Radioactive uis dangerous

Beta particle or Gamma ray radiationCan penetrate pipe and soil, can be detected

Liquid stateCan be inject and dissolve into water

84. Suggest the design of nuclear reactor.SuggestionExplanation

Use uranium-235Use as nucler fuel

Nuclear fissionA lot of heat will produce

Boron or Cadmium rad use as control rodsTo control the rate of nuvlear fission and to stop the radiation

Use moderator (graphitr)To slow the motion of neutron to the best reaction rate. So the rate of nuclear fission can be controlled

Bulid thick concrete wallLead or thick concrete wall can prevent the escape of radioactive rays, keep the radiation inside the reactor

Coarbon dioxide or water is use as coolong agentTo remove heat of reaction for turbine generator. This produce steam as heat carrier

Use steamTo turn the turbine and able to generate current

85. Explain the suitability of charactersitic of radioisotopes to be used in sanitiza medical equip,ent


Gamma rayAble to kill ant virus/ bacteria

Longer half lifeNo need to change radioactive frequently

Silid state of matterEasy to handle

High penetrating powerAble to penetrate any equipment to sanitize

86. Explain the suitability of characteristics of radioisotope to be used in detecting the position of blood clot in veins (Deep vein thrombosis)


Use liquid state of matterAble to inject into patient body, dissolve easily

Short half lifeActive in body in short time

Use beta rayAble to penetrate skin

Low ionizing powerMinimum damage to tissue organ

87. Explain the suitability of characteristics of radioisotope to be use in the trace of blockage in the kidney patient.


Use Iodine-123Used as nuclear imaging tracers to evaluate the anatomic and physiologyc function

Gamma rayAble to penetrate trough body, bones and be detected

Low energyDo not cause serious damage in cells

Liquid state of matterEasy to inject to patient body

Short half lifeActive in body in short time

88. Explain the suitability of characteristics of radioisotope to be use in control the thickness of paper in factory


Long half lifeCan be used for long time, no need to replace frequently so, it save cost

Beta rayCan penetrate paper and be detected

Solid state of matterEasy to handle

89. Explain the suitability of characteristics of radioisotope to be use in control the thickness of aluminium sheet in factory.


Long half lifeCan be used for long time, no need to replace frequently7 so, it save cost

Gamma rayCan be penetrate aluminium sheet and be detected

Solid state of matterEasy to handle, does not spill

MAKING DECISION-SECTION C

90. The transmission of electricity over the National Grid Network uses high voltage cables. You are assigned to study the characteristics of cables which could be used as transmission cable. Table 12 shows the characteristics of four transmission cables. Determine the most suitable transmission cable to be used and give reasons for your choice.

Cable

Resistivity /m-1

Density / kg m-3

CostRate of thermal expansion

P3.0 x l0-75 x l05LowHigh

Q1.8 x l0-82 x l03MediumLow

R7.5 x l0-78 x l02HighMedium

S7.0 x l0-84 x l03MediumHigh

Jawapan


Low resistivity To reduce heat loss in the cables

Low density The cables will be lighter

Low cost Cost of project will be lower

Low rate of thermal expansion The cables will not expand under hot weather

Cable QLow resistivity, low density, medium cost, low rate of thermal

expansion

91. You are required to build a hydrometer that can be used to measure densities of concentrated acids.Table 11.1 shows the characteristics of 4 types of hydrometers L, M, N and O. Decide which hydrometer is most suitable and give reasons.

HydrometerType of material of hydrometerDiameter of capillary tube/ cmDensity of shots/ kgm-3Diameter of bottom bulb/ cm

LPlastic/Plastik0.510001.0

MPlastic/Plastik2.013003.0

NGlass / kaca0.598003.0

OGlass/ kaca2.080001.0

Jawapan


Material made from glassGlass does not corrode with acid

Small diameter of capillary tubeTo increase the sensitivity of the hydrometer

High density of shotsMakes the hydrometer stays upright

Big diameter of bottom bulbTo obtaine a bigger upthrust.

Choose N

N is made from glass, has small diameter of capillary tube, high density of shots and a big diameter of bottom bulb

92. As a researcher , your duty is to study the characteristics of a material to make a water heater. You are given four choices of metal type T, U,V and W. The table below shows the characteristics of the four metals.Determine the most suitable metal to be used as the material to make the heater and give your reasons. MetalThe cross sectional areaMelting Point Specific Heat CapacityLength

TSmallerLowHighLong

ULargerHighLowShort

VSmallerHighLowLong

WLargerHighLowShort

Jawapan


Smaller surface areathe resistance is higher

High melting pointnot easy to melt

Low specific heat capacitythe temperature arises shortly

Long (coiled) metalto increase the resistance

Choose Vbecause it has,smaller surface area, high melting point, low specific heat capacity and long metal

93. You are given four choices of metals P, Q, R and S. The table below shows the characteristics for the four metals. Determine the most suitable metal to be used as the material to make the boat and give your reasons.

MetalShapeDensitySpecific Heat CapacityStrength

PStreamlined 900LowHigh

QOval 452HighHigh

RCircle387LowHigh

SStreamlined 500HighHigh

Jawapan

Characteristic/cirriReason/Sebab

Streamline / larusreduce the resistance of water/

Density /ketumpatan rendah higher buoyant force/ daya apungan tinggi

Specific heat capacity high / absorbs heat slowly/serap haba dengan perlahan

High strength / Kekuatan tinggi Difficult to damage / sukar rosak

Choose Sbecause its streamline,low density, high specific heat capacity and high strength

94. A student plans to fix a lamp in his room. Table 12.1 shows the features of 4 different types of lamps. Explain the suitability of each feature in Table 12.1 and then determine the most suitable lamp to be used. Give a reason for your choice

Type of lampPower Efficiency Life SpanPrice

Compact fluorescent lamp18 W50 %7000 hoursHigh

Filament lamp75 W12 %1000 hoursLow

Long fluorescent lamp20 W45 %14000 hoursMedium

Round fluorescent lamp24 W40 %10000 hoursHigh

Jawapan


Low power lampSafe cost//electric bill

High efficiencyThe room looks brighter//high output power//less power wastage

Long life spanNo need to replace often

Low priceSave money/cost

Long fluorescentLow power with highest efficiency, long hours of life span and low price

95. Table 11.1 shows 5 materials which can be used to make an optical fibre. You are asked to investigate the characteristics of the materials in Table 11.1 which could be used to make the optical fibre.

Explain the suitability of each characteristic and hence, determine the most suitable material to be used to make the optical fibre. Give a reason for your choice.

MaterialRefractive index% of light energy absorbedRigidityStrength

P1.752 %StrongWeak

Q1.8010 %WeakStrong

R1.702 %WeakStrong

S1.523 %StrongStrong

T1.4810 %WeakWeak

Jawapan


High refractive indexTotal internal reflection can occur easily

Small amount of light energy being absorbed by the materialThe object under observation can be seen clearly // more light can be transmitted

Material with weak rigidityThe optical fibre can be bent easily

Material with great strengthThe optical fibre can last longer/not easily spoil

Material RHigh refractive index, low % of light energy absorbed, weak rigidity and great strength

96. You are asked to investigate the characteristics of hot air balloon as below. Explain the suitability for each characteristic for the hot air balloons and then determine which hot balloon will move up the fastest into the air. Give a reason for your choice

Jawapan

CharacteristicExplaination

Volume of the balloon is highDisplace a larger amount of air/

Produce a higher buoyant force.

Density of the balloon material is lowLower mass/Light

Gas temperature is highProduce a maximum expansion of balloon.

Total of mass is lowUpwards resultant force is higher/ Balloon move upwards faster.

Choose QBecause it has a high volume,the density of the balloon material is low,the gas temperature is high and the total mass is low.

97. Table 11.1 shows the characteristics of five types of materials that can be used for making the soles of the trekking shoes. You are asked to study the characteristics of the materials shown in Table 11.1. Explain the suitability of each characteristics in Table 11.1 and then determine the most suitable material to be used. Give a reason for your choice.

Type of

materialDensity

(Kg/m -3)Number of studs x Area of 1 studExpansion effectAbility to stretch

P8206 x 30 cm2LowGood

Q7008 x 30 cm2LowGood

R7205 x 30 cm2MediumAverage

S7504 x 30 cm2HighPoor

T8803 x 30 cm2HighPoor

JawapanCharacteristic Reasons

Low densitySmall mass/light

Many/fewer/very few studsGives extra/higher grip

Expansion effect is lowAlways fits/Does not loosen when hot.

Ability to stretch is goodLess stress on the feet/Can be pushed in all directions/

Can walk on uneven surface.

The most suitable material is Q

Because it has a low density,many studs,low expansion effect and good ability to stretch.

98. Table 12.2 shows the characteristics of five radioisotopes P, Q, R, S and T. As a factory engineer, you are required to determine the most suitable radioisotope that can be used by the system to ensure the volume of guava juice is uniform.Study the characteristics of all 5 radioisotopes and explain the suitability of the aspects.Determine the most suitable radioisotope and give the reason for your choice.

Radioisotope

Radioisotop

Half life

Separuh hayatTypes of ray

Jenis sinarState of matter

Keadaan jirimIonising power

Kuasa pengionan

P7 hoursalfasolidhigh

Q10 daysbetaliquidmoderate

R100 daysgammasolidlow

S10 yearsgammaliquidhigh

T30 yearsbetasolidlow

JawapanCharacteristicsExplanation

Has a long half-lifeCan be used for a long time hence save cost

Emits betaCan penetrate box and liquid and is less

dangerous than gamma

Solid formEasy to handle and contain.

Low ionising powerDoes not change the state and taste of juice.

Radioisotope TIt has long half life, emits beta, in solid form and has low ionising power.

99. You are assigned to investigate the design for the location to keep the boats and the characteristics of the retaining wall as shown in Diagram 12.2 based on the following aspects:

- the location to keep the boat

- material used for the retaining wall

- the height of retaining wall

- size of slit

Explain the suitability of the location and the characteristics of the retaining wall and determine the most suitable design to keep the boat safely.

Jawapan

Characteristic Reasons

BayWave is calmer

Concrete retaining wallStronger/ / lasting

High wallPrevent high wave

Smaller opening/aperture / slit of

retaining wallDiffraction obvious //low wave energy

Choose PAt bay, concrete retaining wall , high wall and smaller slit

100. Diagram 11.4 shows five designs of Newtons Cradle, P, Q, R, S and T, with different specifications. You are required to determine the most suitable design to make the ball at the end swings up to higher level and at bigger speed. Study all the five designs from the following aspects:

The arrangement of the balls

The type of material used to make the balls

the number of string used to hang the balls the position of the ball to start the oscillation

Jawapan

Characteristic Reasons

The balls touch each other

This will reduce losses of energy which will reduce the speed of the

balls

The type of material used to make the

balls is steelSteel balls are hard and produce highly elastic collision. Energy can

easily propagates through the intermediate balls.

Two strings used to hang each ball

This string arrangement restricts the balls movements to the same plane. the position of the ball to start the oscillation

High position of the ballHigh potential energy and will change to high kinetic energy. The last end ball will swing at bigger speed.

The most suitable design is Qbecause the ball s touch each other, made from steel, use two strings attached to each ball and the initial position of the ball is high

12V,24W

114998994 physics spm paper 2 tips 89 modification and 11 decision making question and answer

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