bengkel2012.pptx

Slide 1

The thickness of lens in diagram 2.1 is compare to lens diagram 2.2

Diagram 2.1Diagram 2.2The focal length in diagram 2.1 is compare to diagram 2.2The size of image produced in diagram 2.1 is compare to diagram 2.2.thickershortersmaller

Thickness of the spring wire

Maximum height reached by the ball

Relate :Thickness and maximum heightThickness and elastic potential energy

Compare depth of sinking :Compare load : Area on contact :Relate depth of sinking and pressureRelationship Pressure and areaDepth of sinking on diagram 3.1 is deeper than diagram 3.2 The load of diagram 3.1 is equal to diagram 3.2The area of contact in diagram 3.1 is smaller than Diagram 3.2The deeper the depth, the higher the pressureWhen the area increaes,the pressure decreases

Explaination question3 or 4 marks

Submarine on surface submerge ( 3 marks)Ballast tank

Fill with waterWeight increasesWeight = buoyant forcePartly filledWeight > buoyant forceSubmarine submerge

Paper burns, convex lens, sun ray

The parallel rays of the sun will pass through the a convex lens

2. After entering the lens, the light rays is focused at the principal focus of the lens

3. At the principal focus, the light ray is focused on one small area

4 Heat increases, paper burn

Thermal equilibriumHeat flowHot to coldThermal equilibrium achieved.Temperature of water = temp of thermometerNo more heat flow

High pitch , only C , low pitch until AHigh pitch high frekuensi Low pitch low frekuensi long wave length Short wave length will diffract until C only

Specific latent heat of vaporization of water is absorbed

Air movement velocity increases

Evaporation rate increases

Sweat cold rotating fan Sweat is being evaporated

Copper block volume bigBowl copper volume small

Small volume small Uptrust small

Block sink because weight > uptrust

Sheet float because weight = uptrust

Diagram below shows a sailboat.

You are required to give some suggestions to design a sailboat which can travel faster. Using the knowledge on motion, forces and the properties of materials, explain the suggestions based on the following aspects:

the surface of the boardthe shape of the boardmaterial used for the sailthe size of the sail

smooth surface / coat with waxstreamline shape

low density material

Wide size

water-proof material

Type of material used as the cap of the thermal flaskType of inner wall and outer surfaceThe density of material usedThermal strength of the flask

ModificationReasonPlastic stopperReduce heat loss through conductionVacum spaceReduce heat transfer

Comfort of the person who will use the lamp.

Reduce the heat from the desk lamp

Design of the lamp desk

Safety features of the lamp

Energy efficiency of the lampUse flourescent lampBigger cover with white colourAdjustable stand Energy saver lampConnect earth wire

CapacitySafety features

Power

Stability and other relevant aspects

Section B

variablesManipulated : depth of water ( real depth)Responding: position of image (apparent depth)

Constant: density of water

Inference :Depth of water affect the position of image.

Hypothesis : when real depth increases, the apparent depth increases.

Aim :To investigate the relationship between depth of water ( real depth ) and position of image ( apparent depth)

Apparatus and material :

tall beaker, meter rule, pins, cork, water, retort stand

procedureMention manipulated quantity :Real Depth : start experiment with what depth?? Fill the beaker with water to a height of 20 cm

b) Method of measuring responding variable : apparent depth With meter rule, measure the apparent depth.Repeat experiment : Repeat experiment with different depth such as : 30 cm, 40 cm, 50 cm and 60 cm.

Tabulate dataReal depth / D ( cm)Apparent depth / d (cm)2030405060

Analyse dataApparent depth / d ( cm )Real depth / D (cm)

variableManipulated :

massResponding :Period oscillationConstant : Number of oscillation

inference

____________________ affect

_______________________massPeriod oscillation

hypothesis

When increases, increasesmassperiod of oscillation

aimTo investigate the relationship betweenand massperiod of oscillation

Apparatus and arrangementHacksaw blade, stop watch, plasticine and G clamp.

Method of controlling manipulated variableManipulate variable : masscontrol : the first mass

Plasticine with a mass of 50 g is clamped.

Method of measuring responding variableResponding variable : period

Measure pressure using : stopwatchUsing stop watch , measure the time taken for 20 complete oscillation, calculate the period and record the data

Analyse data

Mass / gPeriod / s2030405060

Graph

Mass / gPeriod / s

variableManipulated :

forceResponding :Extension of thespringConstant : Diameter of the spring

inference

____________________ affect

_______________________forceextension of the spring

hypothesis

When increases, increasesforceextension of the spring

aimTo investigate the relationship betweenand forceextension of the spring

Apparatus and arrangementSpring, slotted weight, retort stand, meter rule

Method of controlling manipulated variableManipulate variable : forcecontrol : the first mass of slotted weight

Slotted weight of 50 g is attached to the spring.

Method of measuring responding variableResponding variable : extension of the spring

Measure pressure using : meter ruleUsing meter rule, measure the length of the spring .

Analyse data2030405060Mass ( g)Force ( N)Length of the spring ( cm)Extension of the spring ( cm)500.51001.01501.52002.02502.5

Graph

Force / NExtension of the spring / cm

Paper 3 Bahagian A

SECTION A : Question 11(a)(i)Manipulated variable : ____________________

1(a)(ii) Responding variable : ____________________

1(a)(iii)Constant variable: ____________________ EXAMPLE:

A student carries out an experiment to investigate the relationship between temperature, , and the volume, V, of trapped air. A beaker is filled with cold water until the air column in the capillary tube is totally immersed. A thermometer is put into the water to determine the temperature of the water. The arrangement of the apparatus for the experiment is shown in Figure 11.1.

Temperature, Volume, V



1(a)(iii)Constant variable: ____________________

12

0

l1Figure 11.2 : Temperature, = 30 C length, l = cm

m.vr.vTemperature, Length, l



1(a)(iii)Constant variable: ____________________ (depends on the experiment)

MISTAKES!!!Which of the following is possibly a constant variable?A) Mass B) Thermometer C) AirA) Water B) Stopwatch C) TimeA) Length B) Air column C) Ruler

SECTION A : Question 11(b) Based on Figures 11.2, 11.3, 11.4, 11.5, and 11.6, determine l when is equal to 30 C, 35 C, 40 C, 45 C and 50 C.

Tabulate your results for l and V for each value of in the space below.

/ Cl / cmV / cm33035404550

SECTION A : Question 1Spot the errors!t1t2tmeanTT2l1717.617.30.870.762022.42222.21.111.23302524.624.81.241.54402828.828.41.422.025030.83130.91.552.460

No unit!Not consistence!

SECTION A : Question 1Spot the errors!

Unit at the wrong place!lt1t2tmeanTT220.0 cm17.0 s17.6 s17.3 s0.87 s0.76 s230.0 cm22.4 s22.0 s22.2 s1.11 s1.23 s240.0 cm25.0 s24.6 s24.8 s1.24 s1.54 s250.0 cm28.0 s28.8 s28.4 s1.42 s2.02 s260.0 cm30.8 s31.0 s30.9 s1.55 s2.40 s2


Wrong unit!Not consistence!

l/ cmt1 / st2 / stmean / sT / sT2 / s20.0 17.017.6 17.3 0.8650.748 30.0 22.4 22.0 22.2 1.11 1.232 40.0 25.024.6 24.8 1.24 1.537 50.0 28.028.8 28.4 1.42 2.016 60.0 30.8 31.0 30.9 1.545 2.387


No error!l/ cmt1 / st2 / stmean / sT / sT2 / s220.0 17.0 17.6 17.3 0.87 0.76 30.0 22.4 22.0 22.2 1.11 1.23 40.0 25.0 24.6 24.8 1.24 1.54 50.0 28.0 28.8 28.4 1.42 2.02 60.0 30.8 31.0 30.9 1.55 2.40

GOOD ANSWER!

SECTION A : Question 1What is a GOOD graph?1) Starting at origin (0,0)2) Write quantities and units on x-axis and y-axis3) Has uniform scale4) All points are transferred correctly5) Draw one straight line and intersect any of the axes6) Distribute other points equally

Plotting the graph: on the graph paper, plot graph T2 againts lRemember to write the quantity & unitsT2 / s2l / cmRemember to choose a good scaleCarefully transfer all points.....Draw the best line

SECTION A : Question 1

BAD GRAPH!


Accepted graph


Rejected graph

more than 1 cm


Rejected graph

more than 0.5 cm


Conclusion

abA) a is inversely proportional to b B) a is directly proportional to b C) a is linearly increasing with b



ConclusionA) a is inversely proportional to b B) a is directly proportional to b C) a is linearly increasing with b A) a is inversely proportional to b B) a is directly proportional to 1/b C) a is linearly increasing with 1/b

ab

a1/b


2(a)(i) RelationshipA) a is inversely proportional to b B) a is directly proportional to b C) a is linearly increasing with b A) a is inversely proportional to b B) a is directly proportional to 1/b C) a is linearly increasing with 1/b

ab

a1/b


2(a)(i) Relationship




2(a)(ii) Determine Corresponding Value : determine the value of P when h = 3.0 cm

h / cmP / Nm-21.02.03.01.02.03.04.0

P = 4.0 Nm-2


2(a)(ii) Determine Corresponding Value : determine the value of m when is 4.0

1/m / g-1 / C0.10.20.31.02.03.04.0

1/m = 0.3 g-1 m = 3.3 g


2(b)(i) Determine Gradient

1/m / g-1 / C0.10.20.31.02.03.04.0

Gradient, l = 4.0 C 0.4 g-1 l = 10.0 C g

y

x

Triangle must at least 4 x 5 Checked substitutionRemember unitGradient must be in decimalnumber. No fraction.0.4

Heat produce from an experiment can be determine by using the fomulaQ = ml,Where l is the gradient and m is the mass.Calculate the value of heat when mass is 2.0 kg.2(b)(ii) Calculation problem (involving the gradient)


2(c) Calculation problemReminder!1) Check for the conversion of units2) Substitute figures at the correct places3) Write the final answer in decimal number (Do not give the answer in fraction!!!)4) Do not forget the UNIT

Q = mlGradient : l = 10.0 J g-1 Mass = 2 kg Q = 2 x 10Q = 2 000 x 10Q = 2 x 104 J = 20 kJ2000 g10 000 J kg-1


2(d) PrecautionReminder!1) It is NOT SAFETY PRECAUTION!!!Take few readings and find the averagePosition of eyes is perpendicular to the scalemethodreasonto reduce random errorto avoid parallax error

Chapter by chapter

2.1 Analysing LinearMotion : distance, displacement, speed, velocity, acceleration

2.2 Analysing MotionGraphs : interpret and analyse graph

2.3 Understanding Inertia : explain what inertia is.relate mass to inertia.give examples of situations involving inertia.suggest ways to reduce the negative effectsof inertia

2.4 Analysing Momentum : define the momentum of an object.define momentum, p as the product of mass,m and velocity, v, i.e. p = mv.state the principle of conservation ofmomentum.describe applications of conservation ofmomentum.solve problems involving momentum

Understanding the effects of a Force

determine the relationship between force,mass and acceleration, i.e. F = ma.

solve problems using F = ma.

2.4 Analysing Momentumdefine momentum, p as the product of mass, m and velocity, v, i.e. p = mv.state the principle of conservation of momentum.describe applications of conservation of momentum.

describe the effects of balanced forces acting on an object.describe the effects of unbalanced forces acting on an object.determine the relationship between force, mass and acceleration, i.e. F = ma.

Understanding the effects of a Force

Analysing Impulse and Impulsive Force

explain the effect of increasing or decreasing time of impact on the magnitude of the impulsive force.describe situation where an impulsive force needs to be reduced and suggest ways to reduce it.describe situations where an impulsive force is beneficial

Understanding Work, Energy, Power and Efficiencystate that when work is done energy is transferred from one object to another.define kinetic energy define gravitational potential energy state the principle of conservation of energy.

Understanding Elasticity

Paper 3Section B

Answer for question 1 Manipulated variable : mass ( of the slotted weight)Responding variable : volume of the slotted weightConstant variable :density

V0 = 27 cm3

m = 50.0 kg, V1 = 33 cm3, V = 6 cm3m = 100.0 kg V1 = 39 cm3, V = 12 cm3m = 150.0 kg V1 = 45 cm3, V = 18 cm3m = 200.0 kg V1 = 51 cm3, V = 24 cm3m = 250.0 kg V1 = 57 cm3, V = 30 cm3

Mass / gVolume of water / cm3Volume of slotted weight/ cm3

50.033.06.0100.039.012.0150.045.018.0200.051.024.0250.057.030.0

Answer for question 2 (a)a)(i) a 1/x

(ii) a = 12, 1/x = 0.5. x = 2.0 cm

(iii) Gradient , m = 24 cm3

2(b) = m / l = 24 / 20.0 = 1.2 cm

2(c) v = f = 1.2 x 12 = 14.4 cm s-1

2(d) The position of eye must perpendicular to the reading scale to avoid parallax error

Paper 3 Bahagian A

Graph

Force / NExtension of the spring / cm

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