1 Intro to Physics

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  • 1Phenomena & Occurrence Around us Field of study in physics1. Car racing

    2. cooking in the kitchen

    3. rainbow in the sky

    4. Shadow on the ground

    5. Nuclear bomb

    6. Light bulb lights up during night

    7. communicating using mobile phone

    8. Memory chip in a computer

    1.1

    1.________ & _____Investigate theaction of force andmotion

    2. __________Studies theinfluence of heaton differenttypes of matter

    3. _________Explains thedifferentphenomenadue to light

    4. ________Understand theproperties ofdifferent typesof waves andtheir uses

    5. _________________Investigatesthe interactionsof electric &magnetic fields

    6. _______Studies theuse ofelectronicdevices invarious fields

    7. _________Study of nuclearstructure andtheir application

    Fields of studyin physics

    What isPhysics?

    Study of ___________ phenomena and the properties of ___________

    Recognise the physics in every-day objects & in natural phenomena

  • 2Physical Quantities is a physical characteristic that can be _______.

    The value of the measurement consists of a numerical ___________ and a _________

    Examples : _________________________________________________________

    All physical quantities can be classified into two groups :1.__________________________ 2. _______________________

    List of 5 basic physical quantities and their units.

    Base quantity Symbol S.I. Unit Symbol for S.I. Unit

    Length

    Mass

    Time

    Current

    Temperature

    Determine the derived unit for the following derived quantities.

    Derivedquantity Formula Derived unit

    Name ofderived unit

    areaarea = length x width

    m x m = m2

    volume volume = length x width x height m x m x m = m3

    densityvolumemassensityd

    1.2

    In learning physics, we need to carry out investigations. We gatherinformation through observations and taking measurement. We measuremany types of physical quantities

    What arebasequantities?

    Base quantities are quantities that cannot be _____________ in termsof other base quantities.

    What arederivedquantities?

    Derived quantity is one which obtained by ___________ base quantities bymultiplication, division or both these operations. Its unit is derived from asimilar combination of the base units.

  • 3Derivedquantity Formula Derived unit

    Name ofderived unit

    velocitytime

    ntdisplacemeelocityv

    momentummomentum = mass x velocity

    kg m s-1

    Accelerationtime

    velocityinchangeonaccelerati

    Force force = mass x acceleration kg m s-2 Newton (N)

    pressureareaforcepressure

    weight weight = mass x gravitationalacceleration

    workwork = force x displacement

    powertimeworkpower

    kineticenergy

    2velocitymassK.E 21

    potentialenergy

    P.E = mass x gravitational acceleration xheight Kg ms

    -2 Joule (J)

    charge charge = current x timeAmpere second(As) Coulomb (C)

    voltagechargeworkvoltage J C-1 Volt (v)

    resistancecurrentvoltageresistance v A-1 Ohm ()

    Note that the physical quantities such as width, thickness, height, distance, displacement,perimeter, radius and diameter are equivalent to length.

    Exersise 1The extension of an elastic spring is directly proportional to the stretching force acting on it. Itcan be shown by the following formula:

    F xF = kx where F = the force (unit N)

    k = spring constantx = the extension (unit m)

    Determine the value of the spring constant k.

  • Exercise 2

    Write th owin s in standard form :

    a. s of 6 370 000 m =.b. of a = 0.000 000 000 000 000 000 000 000 000 000 911 kg =...

    c. f a p .000 03 m =

    d. eter = 0.000 000 072 m = ...

    e. leng = 0.000 000 55 m = ..

    The list efixe

    102101

    10-110-2

    Expressquantitiesusingstandardform

    The values of measurements which is either very large of very smallare written in Standard Form so as to be neater, brief and easier toread.

    Standard form = A x 10n , 1 < A < 10 and n = integer

    Exprquanusinprefi

    is used to simplify the expression of very big or very smallical values of physical quantities.

    1012

    109

    106

    103

    100

    10-3

    10-6

    10-9

    10-12g quantitie

    the earth =n electron

    article = 0

    of an atom

    th of light

    s :

    Prefixnumere foll

    RadiuMass

    Size o

    Diam

    Wave

    of pr

    esstities

    gxes4

    Prefix Value Standardform

    Symbol

    Tera 1 000 000 000 000

    Giga 1 000 000 000

    Mega 1 000 000

    Kilo 1 000

    Hekto 100

    Deka 10

    Deci 0.1

    Centi 0.01

    Mili 0.001

    Micro 0.000 001

    Nano 0.000 000 001

    Piko 0.000 000 000 001

    Hekto (ha)Deka (da)desi (d)centi (s)

    Tera (T)

    Giga (G)

    Mega (M)

    kilo (k)

    mili (m)

    micro ()

    nano (n)

    pico (p)

  • 53. Complete the table below

    1 Tm = __________ m 1 m = ____________ Tm

    1 Gm = __________ m 1 m = ____________ Gm

    1 Mm = __________ m 1 m = ____________ Mm

    1 km = __________ m 1 m = ____________ km

    1 hm = __________ m 1 m = ____________ hm

    1 cm = __________ m 1 m = ____________ cm

    1 mm = __________ m 1 m = ____________ mm

    1 m = __________ m 1 m = ____________ m

    1 nm = __________ m 1 m = ____________ nm

    1 pm = __________ m 1 m = ____________ pm

    4. Convert the measurement into SI unit and in standard form:

    a. Radio Melaka Frequency of radio wave = 102.3 MHz = _______________________b. Diameter of the earth = 12 800 km = _______________________________________

    c. Distance between the moon and the earth = 383 000 km = ____________________

    d. Mass of the earth = 6 000 000 000 000 000 000 000 000 0000 g = ____________________

    e. The height of Petronas Twin Towers is 452 000 mm = ___________________f. The wavelength of a visible light is 0.00042 mm = _______________________

    4. Convert each of the following measurements into metre, m

    (a) 2.98 Tm =

    (b) 2.98 km =

    (c) 2.98 m =

    (d) 2.98 x 10-1 Gm =

    (e) 2.98 x 10-3 Mm =

    (f) 2.98 x 107 nm

    (g) 2.98 x 104 m =

    5. Convert

    (a) 4 m2 into the units of cm2 (b) 30 cm2 into the units of m2

  • 6(c) 2.5 m2 to unit of mm2 (d) 500 mm2 into the units of m2

    (e) 200 m3 into the units of mm3 (f) 11.5 cm3 into the units of m3

    (g) 72 km h-1 into the units of ms-1 (h) 5 g cm-3 into the units of kg m-3

    6. The table above shows the measurement of length for four different objects.

    Readings7.2 x 10 5 m , 7.2 x 10-2 cm 7.2 x 103 mm and 7.2 x 10- 6 km

    (a) Which reading is the longest ?

    (b) Which reading is the shortest?

    (c) Arrange the readings according descending order.

    (d) Which reading is more than 1 metre?

    .(e) A cube of sides 7.2 x 103 mm . State the volume of the cube in unit of m3

    .

    7. The pressure exerted by a box on a surface is 500 N cm 2. What is the pressure in unitsof Pa? ( 1 Pa = 1 N m - 2 )

  • 7TUTORIAL 1.2

    1. Which of the following physicalquantities is not a base quantity?(2006)A. WeightB. TimeC. TemperatureD. Electric current

    2. Which physical quantity has the correctS.I unit? (2003)

    Physical quantity S.I unitA Temperature CelciusB Time MinuteC Mass NewtonD Length Metre

    3. 30 miliseconds is equivalent to .(2003)A. 3 x 10-6 secondsB. 3 x 10-5 secondsC. 3 x 10-4 secondsD. 3 x 10-3 secondsE. 3 x 10-2 seconds

    4. Which of the following frequencies isthe same as 106.8 MHz? (2004)A. 1.068 x 10-4 HzB. 1.068 x 10-1 HzC. 1.068 x 102 HzD. 1.068 x 106 HzE. 1.068 x 108 Hz

    5. The product of 2.4 x 10-2

    and 5.0 x 10- 4

    isA 1.2 x 10

    6B 1.2 x 10

    5

    C 1.2 x 10- 5

    D 1.2 x 10- 7

    E 1.2 x 10 -8

    6. What is 0.0455 kg expressed instandard form?A 0.455 x 10

    - 1kg

    B 4.55 x 10- 2

    kgC 45.5 x 10

    - 3kg

    D 455 x 10- 4

    kg

    7. The prefixes according to their value inascending order areA Giga,mega,kilo,centiB Mikro,mili,centi,kiloC Mega,giga,kilo,centiD Centi,giga,mikro,mili

    8. Which one of the followingmeasurements is different?A 2.3 x 10 2 mB 2.3 x 10 4 cmC 2.3 x 10 6 mm

    9. Which one of the followingmeasurements is smallest ?A 1.5 x 10 2 kgB 1.5 x 10 7 gC 1.5 x 10 12 g

    10. The volume of a metal sphere is 12 cm3.This volume in units of m 3 isA 1.2 x 10 - 2 B 1.2 x 10 - 3

    C 1.2 x 10 - 5 D 1.2 x 10 7

    E 1.2 x 10 - 9

    11. The velocity of a car is 108 km h-1.What is the velocity in units of ms-1 ?A 20 B 30C 50 D 60E 90

    12. The acceleration of a trolley is 2000 cms- 2. This acceleration in S.I. unit isA 0.002 B 0.02C 0.2 D 2E 20

    13. Which one of the following prefixes isless then 1?A MegaB DesiC Kilo

    14. A car moves with an average speed of75 km h-1 from town P to town Q in 2hours as shown in Figure 1. By usingthis information, you may calculate thedistance between the two towns.

    P QFigure 1

    (a) (i) Based on the statements given, statetwo basic quantities and theirrespective SI units.

    ______________________________

    ______________________________

    (ii) State a derived quantity and its SIunit.

    _____________________________

    (b) Convert the value 75 km/hr to SI unit.

  • 8Study the following description of events carefully and then decide which events requiremagnitude, direction or both to specify them.

    Description of events Magnitude Direction

    1. Walk 500 m and youll find the shop

    2. Walk 500 m left from the junction and youll findthe shop.

    3. The temperature in the room is 25 0C

    4. The location of Ayer Hitam is 60 km to the north-west of Johor Bahru

    5. The power of the electric bulb is 80 W

    6. A car is travelling at 80 km/hr from Johor Bahru toKuala Lumpur

    Scalar Quantities Vector Quantities

    Given the formula: Acceleration = Final velocity Initial velocityTime taken

    From the above formula:Scalar quantities : ____________________________

    Vector quantities : _______________________

    1.3

    DefineScalar &Vectorquantities

    Scalar quantities are quantities that have magnitude but no direction.

    Vector quantities are quantities that have magnitude and direction.

    Give examples of scalar and vector quantities

  • 9Two potatoes are put on thedigital balance but the balancedoes not show any reading.Instead, it shows E.

    E stands for error.The digital balances indicatesE because the potatoes aretoo ________ and their weightis beyond the maximumcapacity of the balance.

    When dried mushrooms areplace on an ordinary weighingscale, the pointer shows 0,Why?

    The weighing scale showszero reading because thedried mushrooms are too_______ for the scale toresponse.

    Activity 1Carry out Hands-on Activity 1.1 on page 1 of the practical book and record your observation inthe table.

    Physical Quantities Instrument Readings

    The length of the laboratory table

    The length of a book

    The diameter of beaker

    The diameter of a copper wire

    The volume of water in a beaker

    The volume of water in a spoon

    The time for 10 pulses of your heartbeat

    The time taken to walk around thelaboratory twice

    1. What criteria do you consider when you choose an instrument to measure a quantity?

    2. Suggest a suitable instrument when measuring the following quantities.(a) The mass of a wooden block(b) The current that flows in a circuit(c) The voltage of a battery

    1.4

    Measure physical quantities using appropriate instruments

    When we measure a physical quantity, we need to consider its magnitude andthen choose a suitable instrument. The magnitude of the quantity should notexceed the maximum capacity of the instrument, and the instrument must besensitive enough to detect and give meaningful measurement of the quantity.

  • 10

    Activity 2The diagram shows the result for four shooters A, B , C and D in a tournament. Everyshooters shot five times .The table shows the conclusion . Write either high / low.

    Shooter Consistency AccuracyA

    B

    C

    D

    Carry out Hands-on Activity 1.2 on page 2 in the practical book.

    The sensitivity of measuring instrument for lengthMeasuring instrument Smallest division (cm) Sensitivity

    low / moderate /highRuler

    Vernier Calipers

    Micrometer Screw gauge

    ExplainAccuracy,Consistency

    Consistency is the degree of uniformity of the measurements.OR

    Consistency is the degree of a measuring instrument to recordconsistent reading for each measurement by the same way.

    When we say the measurements are consistent, we mean that all thevalues of the measurements are close together.

    Accuracy is the degree of closeness of the measurements to the actualor accepted value.

    When we say the measurements are accurate, we are actually sayingthat the values of the measurements are close to the true or accepetedvalue.

    ExplainSensitivity

    Sensitivity of an instrument is the ability to detect a small change in thequantity to be measured.

    The smallest scale division on the measuring instruments shows thesensitivity of the instruments. Thus the more sensitive the measuringinstruments the smaller the scale divisions.

    A vernier calipers is more sensitive than a ruler or a miliammeter is moresensitive than an ammeter. A sensitive instrument is not always anaccurate instrument.

  • 11

    The sensitivity of different types of ammeter.

    Double-scale ammeterRange : 0 1 A / 0 5 A MilliammeterRange : 0 50 mA

    What is the Accuracy /Sensitivity (smallest division)?

    What is the Accuracy /Sensitivity (smallest division)?

    Double scale ammeterAccuracy / sensitivity of upperscale : _____________Accuracy / sensitivity of lowerscale : ____________Reading : ___________

    Which is more sensitive? Why?

    measuring time

    sensitivity : ___________Reading : ____________

    Measurement Temperature

    Sensitivity: _____________.

    Exercise 1:Minah, Mary and Malika were asked to measurethe diameter of a test tube in the laboratory. Theactual diameter of the test tube is 2.75 cm. Eachof them measured the diameter three times atthree different places on the test tube. Theirmeasurements are shown in the table.

    (a) What instrument was used to measure the diameter of the test tube? __________________

    (b) What instrument should we use to get more accurate readings?

    ____________________________________________

    Exercise 2:Group A and group B do an experiment to measurethe period of a simple pendulum five times and theresults are shown in the table.State which groups measurements are moreconsistent and explain why.

  • 12

    Any measurement of a physical quantity has errors or uncertainty.There are two types of errors.

    (a) Systematic errors (b) Random errors

    Systematic errors

    Systematic errors are errors in themeasurement of a physical quantity due toinstruments, the effects of surroundingconditions and physical constraints of theobserver.

    Sources of systematic errors are:(i) Zero errors or end errors

    Zero errors occurs when the instrumentgives a non- zero reading when in fact theactual reading is zero.It can be corrected by adjusting the zeroadjuster on the instrument or bysubtracting zero error from any readingtaken from the instrument.

    (ii) Personal error of the observer.Physical constraints or limitations of theobserver can cause systematic errors.An example is the reaction time.

    Systematic errors can be eliminated orreduced by improving the procedure of takingthe measurements , using a differentinstrument or getting somebody else to makethe measurements.

    Random errors

    The main source of random error is due tothe carelessness of the observer whenmaking a measurement.

    Examples of random errors are:(i) Parallax errors occur when the position

    of the eye is not perpendicular to thescale.

    (ii) Different pressures are applied whenclosing the gap of the micrometer screwgauge when it is used to measure thediameter of a wire.

    (iii) Changes in the temperature during anexperiment.

    (iv) Recording the wrong reading.(v) Mistake in counting

    To eliminate or reduce random errors ,repeated reading are taken.

    To avoid parallax errors:(a) The position of the eye must be

    perpendicular to the plane of the scale.To overcome parallax errors ininstruments with a scale and pointer, e.g.an ammeter often have a mirror behindthe pointer. The correct reading isobtained by making sure that the eye isexactly in front of the pointer, so that thereflection of the pointer in the mirror isbehind it.

    Sample of measuring instruments :

    1 Ammeter : is used to measure ________________________________________________

    pointer mirror pointer mirror

    Pointers image is behind the pointer

    incorret reading correctreading1 2 3

    0 4

    1 2 30 4

    Pointers image can be seen

    Explain types of experimental error and use appropriate techniques to reduce errors

  • 2.Measuring cylinder : is used to measure________________________________________

    3. Ruler : is used to measure ___________________________________________________

    wrong right wrong

    10 11 12 13 14 15 Reading = cm

    4. Vernier calliper

    A venier calliper is used to measure :

    a. _______________________________ b. __________________________________

    A vernier calliper gives readings to an accuracy of _________ cm.

    1 cm on main scale is divided into 10 divisions.

    Length of 1 division on main scale = ________ cm

    Length of vernier scale = ________ cm

    Vernier scale is divided into 10 divisions

    Length of 1 divisions on vernier scale = _______ cm

    Right position of eye (eye are in a line perpendicular to the planeof the scale)

    wrong position of eye

    wrong position of eye

    water

    cm 0 1 2 3 4SKALA

    0

    inside jawsVernier scale

    outside jaws

    Main scale

    The differenct between the main scale andvernier scale is = _______ cm13

  • The diagram below shows a vernier calliper with reading.

    Vernier calliper reading = _________ cm

    Vernier calliper reading = ________________

    Vernier calliper reading = _________

    No Zero error: Positive zero error:

    Zero error = ____________ cm

    Correct reading = observed reading

    0 5 10

    0 1

    0 1 2 3 4 5 6 7 8 9 10

    0 1cm

    Main scale = ____________

    Vernier scale = ____________

    Final reading = ____________

    Find the division ofvernier scale which iscoincides with anypart of the main scalezero error14

  • 15

    5. Micrometer screw gauge.

    A micrometer screw gauge is used to measure :

    a. _______________________________ b. ____________________________

    No zero error Positive zero error

    Zero error = __________

    One complete turn of the thimble(50 division) moves the spindle by0.50 mm.Division of thimble

    = ______________

    = ______________

    A accuracy of micrometerscrew gauge = ____________

    Main scale : _________

    Vernier scale : ________

    Total reading : ________

    Main scale : _________

    Vernier scale : ________

    Total reading : __________Negative zero error

    Zero error = ____________

  • Exercise: Vernier Callipers And Micrometer Screw Gauge

    1. Write down the readings shown by the following(a)

    (b)

    (c)

    (d)

    2. (a) The following diagram shows the scale of a vernier calliper when the jaws are closed.

    Zero error = __________ cm

    (b). The following diagram shows the scale of the same vernier calliper when there are

    40 pieces of cardboard between the jaws.

    0 5 10

    0 1

    0 5 1

    6 7

    0 5 10

    7 8

    0 5 10

    4 5A B

    QP

    0 5 10

    5 6

    0 5 10

    0 1

    Answer: _____________

    Answer:: ________________4.27 cm..

    Answer:__________________________

    Answer:

    Reading shown = ________ cm16Corrected reading = ________ cm

  • 3. Write down the readings shown by the following micrometer screw gauges.(a) (b)

    Answer: . Answer:..

    (c) (d)

    Answer: ____________

    4. (a) Determine the readings of the following micrometer screw gauges.

    Zero error = ___________ Zero error = ________

    (b) Determine the readings of the following micrometer screw gauges.

    5. Write down the readings shown by the following micrometer screw gauges.

    (a) (b)

    Answer: ____________

    35

    400 5

    30

    0 5 10 35

    20

    250

    0 0

    45

    5

    0

    0

    5

    0

    0 0 5

    15

    20

    15

    200 5

    Zero error = __________ Reading shown = _____________

    Corrected reading = _____________

    20

    250

    15

    200 517

    Answer: ___________Answer: _________________

  • 18

    TUTORIAL 1.3

    1. The ability of an instrument givesconsistent reading , when repeatedreadings are taken is called asA accuracy B precisionC sensitivity D error

    2. Which of the following should be thesmall value ,so that the precisionbecomes high?A Actual value B MeanC Relative error D Relative

    deviation

    3. The ability of an instrument to detect aslight change that occurs in themeasured quantity is called asA precision B accuracyC sensitivity D error

    4. The accuracy of an instrumentincreases ifA the number of significant figures

    increasesB the relative deviation relative

    increasesC the relative error increases

    5. Based on the table below, what are themeasuring instruments J, K and L?

    Measuringinstruments

    Measurement

    J 2.52 0.01 cmK 15.20.1 cmL 125.40.1 g

    J K LA Micrometer Vernier Spring

    screw gauge calipers balanceB Micrometer Vernier Triple beamScrew gauge calipers balance

    C Vernier Metre Triple beamcalipers ruler balance

    6. Which of the following is true?A The parallax error is not effected to

    the accuracyB The accurate instrument is also the

    sensitive instrumentC The accuracy increases when the

    measurement nearest to actualvalue.

    7. A, B, C and D show the shooting markson a target. Which marks can explainthe concept of precision of ameasurement? (2005)

    8. Which of the following is most likely toshow an accurate shooting but not sopresicely?

    9. The following table shows the readingsmeasured by using different measuringinstruments X, Y dan Z.

    Measuringinstrument

    Reading /mm

    XYZ

    2.38526.5

    Which of the following is true?X Y Z

    A Ruler Vernier mikrometercalipers screw gauge

    B Vernier Mikrometer Measuringcalipers screw gauge tape

    C Measuring Ruler VernierTape calipers

    D Mikrometer Ruler VernierScrew gauge Calipers

    10. Table shows readings of the thicknessof a book measured by four differentstudents. Which of the studentsrecorded the true readings.

    Student

    Ruler/ cm

    Verniercalipers/ cm

    Mikrometerscrewgauge/cm

    ABCD

    WXYZ

    2.172.1742.172.2

    2.22.22.1742.17

    2.1742.172.22.174

  • 19

    11. Which comparison is correct about thesensitivity of the vernier calipers andthe metre rule when measuring thethickness of a wire? (2004)

    Vernier calipers Metre ruleA Low sensitivity Low sensitivityB Low sensitivity High sensitivityC High sensitivity Low sensitivityD High sensitivity High sensitivity

    12. Which of the following accuracy of themeasuring instruments is true?

    Measuringinstruments Accuracy

    A Ruler 1 mmB Vernier calipers 0.001 cmC Mikrometer 0.1 mm

    screw gauge

    13. The focal length of a convex lens is 12cm. If the focal length is measured byusing a ruler, the reading recordedought to beA 11.9 cm B 12.0 cmC 12.00 cm D 12.1 cm

    14. The following diagram shows a verniercalipers.

    What is the reading of the verniercalipers ?

    A 3.17 cm B 3.08 cmC 2.18 cm C 2.07 cm

    15. The thickness of a paper is measuredby using a micrometer screw gaugeshould be recorded asA 2 mm B 2.1 mmC 2.14 mm D 2.142 mm

    16. Figure(a) shows the existence of zeroerror of a vernier calipers. Figure(b)shows the reading of the verniercalipers for diameter of metal sphere.

    The actual reading of diameter of themetal sphere isA 2.02 cm B 2.04 cmC 2.06 cm D 2.08 cm

    17. Diagram shows a micrometer screwgauge reading when it is closed at itsgap.

    The subsequent readings must becorrected byA adding 0.02 mmB subtracting 0.02 mmC adding 0.03 mmD subtracting 0.03 mm

    18.

    Based on the diagram above, thethickness of a sheet of paper isA 3.25 cm B 3.75 cmC 0.325 cm D 0.0375 cm

  • 20

    19. Figure(a) shows the existence of zeroerror of a micrometer screw gauge.Figure(b) shows the reading of themicrometer screw gauge for diameterof metal wire.

    The actual reading of diameter of themetal wire isA 8.30 mm B 8.32 mmC 8.80 mm D 8.82 mm

    20. Which of the following will increase thesensitivity of a mercury-in-glassthermometer/

    Glassstem wall

    Capillarytube

    Size ofbore

    A thick wide bigB thin narrow bigC thick wide smallD thin narrow small

    21. The current flows through a metalconductor is between 0.01 A to 0.05A. Which ammeter is most suitable touse?A Ammeter range 0-1AB Ammeter range 0-5AC Ammeter range 0-10 mAD Ammeter range 0-50 mA

    22. A,B, C and D show parts of fourdifferent balance scales. Which balanceis the most sensitive? (2007)

    Structure Question1. Figure 2.1 and Figure 2.2 show two

    methods used by a student to measurethe width of a piece of paper.

    (a) State the SI unit of the width of thepaper.

    ______________________________

    (b) Why are the measurements nottaken from the zero marks?

    ______________________________

    (c) Which method gives a moreaccurate measurement?

    ______________________________

    (d) Name the error made when themethod shown in Figure 2.2 isused.

    ______________________________

    2. Figure 3 shows the meniscus of waterin a measuring cylinder K, L, and M arethree eye positions while measuringthe volume of the water.

    (a) (i) Which of the eye positions is correctwhile taking the reading of thevolume of water?

    (b) The water in the measuring cylinder isreplaced with 30 cm3 of mercury.InFigure 4, draw the meniscus of themercury in the measuring cylinder.

  • 21

    3. Figure(a) shows the jaws of a verniercalipers without tigh any object.Figure(b) shows the jaws of the verniercalipers tigh a test tube.

    (a) What is the function of P?

    _____________________________

    (b) What is the smallest division onthe vernier scale?

    _____________________________

    (c) State the diameter of the testtube in metre.

    _____________________________

    4.

    Diagram above shows the reading of amikrometer screw gauge for thethickness of 5 sheets of paper.

    (a) What is the number of revolutionof the N scale .

    (b) Determine the thickness of a sheetof the paper in cm.

    (c) Give the name and the function ofM.

    _____________________________

    _____________________________

    (d) State a precaution to be takenwhile taking measurements byusing the micrometer screwgauge.

    _____________________________

    _____________________________5.

    Diagram above shows a thermometer.

    (a) Name component

    (i) P: ________________________

    (ii) Q : _______________________

    (b) State the accuracy of thethermometer.

    _____________________________

    (c) What is the reading of thethermometer?

    _____________________________

    (d) Why does the glass stem wall ofthe thermometer is thin?

    _____________________________

    (e) How should you do to increasethe accuracy of the thermometer.

    _____________________________

  • 22

    (f) Why does the thermometer usemercury?

    ____________________________

    _____________________________

    (g) Draw a dotted line to show thecorrect position of eye in theabove diagram while measuringthe temperature of a substance.

    6. Diagram shows a miliammeter.

    (a) Give the name and the function ofcomponent of

    (i) A : ________________________

    ________________________

    (ii) B : ________________________

    ________________________

    (b) State the accuracy of theammeter

    (c) State the reading of the ammeter.

    (d) State two precautions to be takenwhile taking measurements byusing the ammeter.

    _____________________________

    _____________________________

    7. Diagram (a) shows the scale of amicrometer screw gauge before beingused to measure an object. Diagram(b) shows the scale of an ammeterwithout any current flowing through it.

    Diagram (a)

    Diagram (b)

    (a) What is meant by sensitivity?

    (b) Observe Diagram (a) and (b), andcompare the readings shown by thetwo instruments. Relate thereadings shown by the twoinstruments so that a conclusioncan be drawn based on a relatedconcept of physics.

    [5 marks]

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    When physicists observe a particularphysical phenomenon they will asquestions as to how or why it happens .Ahypothesis will be put forth andexperiments or scientific investigationswill be carried out to prove or disprovethe hypothesis. If the experiments bearout the hypothesis, the hypothesis maycome to regarded as theory or law ofnature. If the dont the hypothesis willbe rejected or modified.In any experiment , the report on theexperiment will be based on theseguidelines and follows a sequence asshown in the following flow chart:

    InferenceEarly assessment that is carried out toanswer the questions raised.

    The inference should be written as :depend onOrThe ..changes as the ...changes

    HypothesisA general statement about the relationship between a manipulated variable and aresponding variable.

    The hypothesis should be written as :The greater the, the greater the.Or The bigger the, the smaller the..

    Manipulated variableThe quantity whose values we deliberately choose to change or a primary variable whichcauses other secondary variable to change.

    Responding variableThe quantity whose value depend on the manipulated variable or a secondary variablewhich changes in response to the change in the manipulated variable.

    Fixed variableThe quantity whose value is kept constant throughout the experiment.

    AimA statement to show the investigation of the variables involve.The aim of the experiment should be written as:To investigate the relationship between ..and

    ApparatusList the apparatus and materials used so that at least a set of data for manipulated andresponding variables can be determined.State the arrangement of the apparatus that can function by drawing a labeling diagram .

    1.5

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    ProcedureState the method of controlling the manipulated variablesState the method of measuring the responding variablesRepeat the experiments at least four times.

    Tabulating the data

    Record the data in the following table

    Manipulatedvariable/unit

    Velocity, v/ ms-1

    Respondingvariable/ unit

    Time, t / s

    The data shown in the table must beconsistent in the number of decimal places inaccordance with the respective measuringinstruments.For example,

    Length, l / cm Time , t /s0 12.82 25.64 39.46 52.28 75.0

    If the data too small or too big use thestandard form number.For example

    Temperature /oC

    10 20 30 40 50

    Density, / kgm-3

    x 104

    9.7 8.5 7.3 6.6 5.1

    Analyzing the dataPlot a graph of ( Responding variable) against (Manipulated variable)

    How to plot the graph ?The title of the graph must be shown.The axes of the graph must be labeled with theunit used.For example:

    The scale chosen must be easy to use.Scales such 1:1 , 1:2 , 1:5 ,1:10 ,1:100 areproffered in plotting a graph.Odd scales such as 1:3 , 1:4, 1: 6, 1:7, 1: 30should be avoided in plotting a graph.

    Make sure the area covered by the plottedpoints must not be less than 50% of the areaof the graph paper.

    For example:

    The scale on the axes must be uniform andclearly marked with value.For example:

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    The best straight line or the best curve graphmust be drawn.The best straight line or the best curve graphis the line that passes through most of thepoints plotted such that it is balanced by thenumber of points above and below the line.The line also must smooth.

    All the points are marked with a symbol suchas a cross or circle and the centre of thecross must accurately positioned.

    It is not advisable to plot graph by joiningpoint to point because the graph obtained isnot smooth.

    How to analyze the data ?(a) Determine the relationship between two variables.

    y is directlyproportional to x.or y xor y = mx

    m = gradient

    y increases linearly withxor y = mx + c

    m = gradientc = intercept on axis-y

    y decreases linearly withxor y = -mx + c

    m = gradientc = intercept on axis-y

    y is inversely proportionalto xor y 1 or y = k

    x xk = constant

    (b)Determine the gradient of the graphExample

    Draw a sufficiently large triangle to calculate thegradient of the graph.State value of the gradient with correct unit.The gradient of the graph is

    m = y2 - y1x2 - x1

    = QRQR

    (c) Determine the certain values from thegraph.

    Certain important values can be obtainedfrom the graph plotted by drawing ahorizontal line or by extrapolating thegraph.

    (d) State the precautions should betaken

    Carry out Experiment 1.1 on page 4 of the practical book and write a report.

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    TUTORIAL 1.3

    1. Which of the following is the bestgraph ?

    2. Which of the following graphs showthat y increases linearly with x?

    3. Hookes law states that applied force Fis directly proportional to the extensionx of spring if its elastic limit is notexceeded. Which of the followinggraphs shows the Hookes Law?

    4. The acceleration, a of an object isinversely proportional to the mass, mof the object under constant force.Which of the following graphsdescribes the relationship between aand m .

    5. Based on the graph above, what is thegradient of the graph?A - 1.5 B - 0.7C 0.7 D 1.0E 1.5

    6. What is the unit of the gradient of thegraph above?A m B m

    2s

    C ms2

    D ms- 2

    7. A student plot a graph for a physicalquantity , Q on axis-y against aphysical quantity ,R on axis xThe relationship between Q and R isgiven by as Q - aR = b , where a and bare constants. The gradient of thegraph isA a B R

    b Q

    C b D a

    8. The resistance R and temperature Tfor an electric conductor is given as R= r + aT with r as the resistance at0oC and a as a constant.A graph of R against T is shown .

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    What is the resistance ,R of theconductor at a temperature 60oC ?

    A 35B 47C 86D 93E 180

    9.

    The equation of the graph above is

    A P = 10Q + 5 B P = 2Q + 10C P = -2Q + 10 D P = 5Q 10

    10. The following figure shows a graph Uversus V.

    Which of the following shows thecorrect relationship between U and V?

    A U = m V + mn

    B U = - m V + mn

    C U = m V + nn

    D U = - n V + mM

    11. A student carries out an experiment tofind out the relationship between thechange in length , y , of a spring andmass, m , of the load on the spring. Thearrangement of the apparatus for theexperiment is shown in Figure 1 . Thelength of the spring when a load isplaced on the piston is l .

    At the beginning of the experimentthere is no load. The length of thespring is lo . The actual length of lo isshown in Figure 2.The experiment is repeated by usingload with mass , m , equal to 0.5 kg ,1.0 kg , 1.5 kg , 2.0 kg and 2.5 kg. Theactual lengths of the spring when thedifferent masses are used are shownin Figure 3, Figure 4 , Figure 5 ,Figure 6 and Figure 7.

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    (a) Based on the aim and the procedure of the experiment state the:(i) manipulated variable

    ________________________________

    (ii) responding variable

    _________________________________

    (iii) constant variable

    ________________________________

    (b) Measure the length of the spring in Figure 2.lo = ___________________

    Measure the lengths l of the spring in Figure 3 , Figure 4 , Figure 5 , Figure 6 andFigure 7 when different load are used.

    In each case, calculate the change in length, y , of the spring where;y = ( lo l )

    Tabulate your results for m ,l and y in the space below.

    (c) On the graph paper , plot a graph of y against m.

    (d) Based on your graph, state therelationship between y and m .

    _________________________________

    _________________________________

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    5

    T2 / s2Graph T2 against l2l / cm

    2 4 6 80 10012. A student carries out an experiment toinvestigate the relationship betweenthe length of a simple oscillatingpendulum ,l , with its period, T.31

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    The experiment is repeated usingdifferent lengths, l, and theircorresponding periods, T, are recorded.A graph of T2 against l , is then plottedas shown above.(a) Based on the graph,

    (i) State the relationship betweenT2 with l.

    _____________________________

    _____________________________

    (ii) Calculate period, T, when thelength l = 45 cm.

    (Show your working)

    (iii) Calculate the gradient of thegraph.

    (b) Using the value of the gradientobtained from (a)(iii) and theequation,

    glT 24

    calculate the acceleration due togravity , g.

    (c) State one precaution for thisexperiment.

    ______________________________

    ______________________________

    13. The graph above represents graph Wagainst V , where W and V are thedistances on a wooden rod.

    (a) Based on the graph state the:

    (i) manipulated variable

    ______________________________

    (ii) responding variable

    ______________________________

    (b) Calculate the gradient of the graph.

    (c) Determine the intercept on(i) axis- W

    (ii) axis-V

    (d) State the equation of the line

    ______________________________

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    22 Pak Ali has a pendulum clock asshown in the diagram below.

    Every day it was observed that theclock was slow about 2 minutes.Pak Ali raised the position of the bobto correct the clock.

    Based on the observations:(a) State one suitable inference that

    can bemade.

    (b) State one appropriate hypothesisfor an investigation.

    (c) With the use of apparatus suchas pendulum bob , string andother apparatus, describe anexperimental framework to testyour hypothesis.In your description, state clearlythe following:(i) Aim of the experiment(ii) Variables in the experiment(iii) List of apparatus andmaterials(iv) Arrangement of theapparatus(v) The procedure of the

    experiment which include themethod of controlling themanipulated variable and themethod of measuring theresponding variable

    (vi) Way you would tabulate thedata

    (vii) Way you would analysis thedata

    23. Diagram 1 and Diagram 2 show twobabies sleeping in their springcradles.The two cradles are extendedwith the same displacement andreleased so that they move up anddown.

    Diagram 1 Diagram 2

    At the beginning, the up and downmovement are the same for bothcradles. But at the end, the cradleshown in Diagram 1 stops earlier thanthe cradle shown in Diagram 2.Using the information

    (a) Make one suitable inference.(b) State one appropriate hypothesis

    for an investigation.(c) With the use of apparatus such

    as spring and other apparatus,describe an experimentalframework to test yourhypothesis.

    In your description, state clearlythe following:(i) Aim of the experiment(ii) Variables in the experiment(iii) List of apparatus andmaterials(iv) Arrangement of theapparatus(v) The procedure of the

    experiment which include themethod of controlling themanipulated variable and themethod of measuring theresponding variable

    (vi) Way you would tabulate thedata

    (vii) Way you would analysis thedata