physics module by spm14ca
DESCRIPTION
SPM 14 PHY TIPSTRANSCRIPT
SULIT SPM14CA
20 TOP LISTS OF DEFINITIONS FOR PHYSICS SPM 2014
Acceleration Rate of change of velocity
Mass Amount of matter in an object
Free Fall When an object falls due to the force of gravity without any influence from any other ext force
Inertia Properties of object to resist any changes when the object is at rest or moving with constant velocity
Impulsive Force Rate of change of momentum
Gravitational Potential Energy
Energy possessed by object due to its higher position in the gravitational field
Buoyant Force Upward force produced by an object when it is partially or completely immersed in the fluids
Heat A form of energy that is transferred from a hot body to a cold body
Specific Latent Heat of Fusion
Amount of heat required to change 1kg of substance from solid to liquid phase without change in temperature
Refraction of Light Bending of light ray at the boundary of two medium as the light ray propagates from a medium to another
Critical Angle The angle of incidence when the angle of refraction is 90°
Focal Length Distance between the focal point and optical centre
Linear Magnification Ratios of size of image to the size of object
Damping Damping is an oscillating system occurs when the system losses energy to the surrounding
Interference Superposition of two coherent waves
Induced Current The current which is produced when there is relative motion of a conductor across a magnetic field
Electromagnetic Induction
Production of an electromagnetic force in a conductor when there is a relative motion between the conductor and the magnetic field
Thermionic Emission The emission of electrons from the surface of a heated metal
Doping A process of adding a small amount of impurities into semiconductors
Nuclear Fission Splitting of a heavy nucleus into two smaller nuclei with the release of energy
SULIT SPM14CA
RAMALAN FOR 2014 (ESSAY)
PAPER 2
Angle
Water rocket / golf / javelin
o 45* : maximum horizontal distance
Arrow Competition
o Slightly higher than target : The path is curved downwards
due to gravitational force
Law of Reflection
o Incidence ray = Reflection angle
Incidence angle greater than critical angle (i > c)
o So that total internal reflection will occur
Smaller critical angle
o Higher refractive index
Shape / Structure
Aerodynamic / Aerofoil : Reduces air resistance
Streamline ( Ship ) : Reduce water resistance
Hydrodynamic ( Submarine ) : Reduce water resistance
Inverted Aerodynamic : Bigger downward force which will
make the vehicle more stable [ Ex : Racing car ]
Dome Shape : Improve acoustic
Cylinderical Shape : Provide uniform magnetic flux [ Ex :
Magnet ]
Sharp : To produce greater pressure [ Ex : Pile ]
Concave / Curved Shape : To produce radial magnetic flux
Hollow : To reduce the impulsive force
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Surface / Colour
Soft : Less water resistance [ Ex : Sail boat ]
Shiny : Good light / heat reflector
White / Bright Colour : Good light / heat reflector
Black / Dark Colour : Good heat absorber
Lager Surface Area : Smaller pressure
o Ex. of advantages of larger surface area
Tractor tyre : Smaller pressure
Sailing boat : Can trap more air
Solar panel : Can absorb more heat
Cooling fins (car radiator) : Rate of heat released is faster
Size
Bigger Size
Can displace more air which will produce a bigger buoyant
force ( hot air balloon )
Can displace more water which will produce a bigger buoyant
force ( water raft )
Can displace more water which will enable the hydrometer to
float ( hydrometer )
Blade for car radiator : Heat released faster
Combustion chamber in jet : More space for the fuel to be
burnt
Propeller : To produce greater forward thrust
Smaller Size Diameter
Bulb of thermometer : Rate of heat transfer is faster
Cooking pot : Rate of heat transfer is faster
Fibre optic : Does not occupy big space
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Bunsen burner (nozzle) : Gas will flow with higher speed
which produce lower pressure region
Rocket (nozzle) : Hot gases can eject at a higher speed which
will produce the backward momentum
Capillary tube in thermometer : High expansion of mercury
Wider
Tyres : Produce low pressure on road / more stable
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PROPERTIES OF MATERIALS
SECTION B / C
Strong / High strength : Does not damage easily
Light : Easier to carry / move faster / high acceleration
Low density : Lighter
High melting point : To withstand high temperature
High boiling point : Does not vaporize easily
Hard : Does not change shape
Low rate of rusting / Corroding : Long lasting
Heavier mass : Larger momentum / withstand high pressure
Low specific heat capacity : Heat transfer is faster
Poor heat conductor : Heat up slowly
Air tight : Less heat loss
High specific heat capacity : Can absorb more heat
Lower rate of oxidation : Long lasting
Soft material : Decrease impulsive force
High thermal conductivity : Transfer of heat better
High specific latent heat of vaporization : Absorb more heat
High elasticity : Bend easily
Thicker lens : High power / bigger magnification
Shorter focal length : Bigger magnification
High refractive index : Smaller critical angle
Bigger radius of curvature of mirror : Brighter image
Concave mirror : Can produce magnifies image
Convex mirror : Has wider view
Low resistance : Power loss can be reduced
Low rate of expansion : Lower resistance
Liquid state : Can flow easily
Solid state : Easier to handle
Low ionising power : Minimum damage to tissue / organ
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Shorter half-life : Decay faster
Longer half-life : Long lasting
Lower centre of gravity : More stable
High viscosity : Less friction
Waterproof material : To prevent water entering
Low freezing point : Does not freeze easily
Low power : Longer focal length
Low resistivity : Increasing the conductivity
Rigid : Not easy to crack
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SECTION C
Helmet (outer shell) : Fibre glass = Stronger / Lighter
Interior shell of helmet : Polystyrene = Reduce impulsive force
Body of vehicle : Carbon fibre = Strong / Lighter
Spring for baby cradle : Copper = Soft / Strong
Building material for ship : Titanium = Stronger / Lighter
Boat : Fibre composite = Lighter / Stonger
Hot air balloon / Parachute : Polyester = Air proof material
Hot air balloon (near the burner) : Nomex = Fire resistance
Kettle : Nichrome = Higher resistance
Electrical wire : Copper = Good conductor
Lamp / Bulb : Fluorescent = High efficiency
Fuse wire : Tin alloy = Low melting point
Transformer : Soft iron = Can be mag / demagnetized easily
Oil : Less air bubbles / Smaller specific heat capacity
Copper : Low resistance
Aluminium : Lighter / Stronger
Steel : Strong
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#FORCES AND MOTION – SPM 14
F = ma
F/m = a [ Lower the mass, higher the acceleration ]
P = m/v [ Lower the density, low the mass ]
P = mv [ Bigger mass, bigger the momentum ]
F = m (v-u)/t [Longer impact time, smaller impulsive force]
Ek = 1/2mv^2 [ Higher speed, higher kinetic energy ]
Eg = mgh [ Higher height, higher the grav. Potential
energy ]
Ee = 1/2Fx , 1/2 kx [ Thicker the spring, more higher the
elastic potential energy ]
Higher position : Higher speed
Moving any object faster : To transfer higher energy to
the object
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POWER
Higher Power
Bulb : Brightness increases
Engine of car : Bigger forward thrust
Lens : Shorter focal length / Bigger magnification
Fan : Higher speed / Higher current
Lowe Power
Bulb : Safe cost
Heating element : Heat of slowly
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MODIFICATION & DESIGNING QUESTIONS
#Rumours are saying that there is a slight change in paper 2 section b/c where they won’t be
providing us any characteristics, aspects & modification anymore which means we can choose any
suitable aspects and list it
IMPORTANT QUESTIONS FOR THIS YEAR
1. A group of fishermen plan to go for deep sea fishing for three
months. The boat that they are using is not suitable and they
decided to make modifications to it. Using appropriate physics
concepts, suggest and explain the modifications that have to be
done to the boat.
Sample Answer
Shape - Streamline To reduce water resistance
Materials used must be strong So boat will not break on impact of water
Materials used - hard So boat does not change shape / balanced
Use sonar system for fish detector As sonar can be reflected back
Install a cooling compartment To lower fish temperature ensure they remain fresh
Smooth surface board Reduce friction towards water
Low density material Lighter
2. Modification for torchlight.
Sample Answer
Use concave share mirror Reflected ray is converging
Bulb at principal focus Reflected ray can form a parallel beam
Batteries connected in series Produce large current
Use copper connecting wire Low resistance
Use strong material such as aluminium alloy Last long
Torchlight must made of waterproof Unaffected by water
3. Design a rocket which can travel outer space with a higher
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acceleration.
Sample Answer
Aerodynamic shape To reduce air resistance
Use low density material It will be lighter
Use liquid oxygen Boosting combustion
Has several stages that can be slip To decrease the mass of the rocket
Increase the size of the combustion chamber More space for fuel to be burnt
4. Explain the modification that should be done to a spring cradle to
support two babies placed at the same time.
Sample Answer
Arrangement of spring must be parallel Can support larger load
Smaller diameter of spring coil Can support larger load
Size of cradle must be large To support two babies at the same time
Spring should be made up of stiff material Can support larger load
Larger diameter of spring wire Higher stiffness of spring
5. Suitable hydraulic pump to raise cars in a motor workshop
Sample Answer
Type of liquid used is oil Oil is suitable because doesn’t evaporate easily
Size of cylinder under the car must be big To produce bigger force to lift the car
Amount of liquid must full Pressure can be transmitted efficiently
Type of material used is steel Rate of oxidation is slow
6. Features of the hot air balloon so that it can rise up fast and safe.
Sample Answer
Bigger size To produce bigger buoyant force
High temperature of air To produce less dense air
More number of burners To produce hot gasses in shorter period of time
Total mass is low Balloon move upward faster
Envelope made of synthetic nylon Strong / lighter
7. Using knowledge on reflection of light, explain the characteristics
of an anti-theft mirror that can be used to have a clearer view of
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the shop’s interior.
Sample Answer
Convex mirror Wider view
Larger diameter More objects can be seen
Bigger curvature of mirror Wider view
Less thickness Avoid multiple image formed
Position: Top corner Can monitor easily by observer
8. Specification for the construction of an auditorium hall.
Sample Answer
Dome shape roof Improve acoustic
Sound proof materials for wall To avoid disturbance from outside
Soft materials for seat To absorb sound
Powerful speakers More louder
Floor covered with thick carpet To absorb sound
9. Specification of fuse wire to prevent damage to the electrical coil
due to overheating.
Sample Answer
Lower specific heat capacity Shorter time to heat and melt
Lower melting point Can melt easily when larger current flows
Smaller diameter of fuse wire High resistance
High resistivity More heat released
High thermal conductivity Transfer the heat better
10. Specification of cables for National Grid Network.
Sample Answer
Cables with bigger diameter Decrease resistance
Cables with small density Lighter
Cables with smaller rate of expansion The danger of the cable snapping is reduced
Cables with lower specific heat capacity Temperature rise will be lower
11. Design a loudspeaker which can produce a loud sound.
Sample Answer
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Shape of magnet is cylindrical It will produce uniform magnetic field
The coil is placed surrounding the magnet To increase the effectiveness of counter react between the magnetic field
Cone is made of light material It can easily vibrate
A.C power supply is used Audio signal varies with the current
Material for body of loudspeaker is metal To ensure loudspeaker is strong
12. Determine transformer with the highest efficiency.
Sample Answer
Type of wire – copper wire Low resistance
Type of core - soft iron Can be mag / demagnetized easily
Design of core - laminated Reduce energy loss due to eddy current
Method of winding – wind the secondary coil on top of primary coil
Reduce flux leakage
13. As a factory engineer, you are required to determine the most
suitable radioisotopes that can be used by the system to ensure the
volume of guava juice is uniform.
Sample Answer
Has a long half life Can be used for a long time hence save cost
Emits beta Can penetrate box and liquid and less dangerous than gamma
Solid form Easy to handle
Low ionising power Does not change the state or taste of juice