*Prepared by : nisaar

*Solve the basic engineering science problems by using related concepts.Organize an appropriate experiments to prove related physics principles.Apply related physics principles in various situations to enhance knowledge.

ENGINEERING SCIENCE*CHAPTER 1: PHYSICAL QUANTITIES AND MEASUREMENT

1.1 Understand the physical quantities 1.1.1 Describe base quantities, derived quantities and the International System (SI) of units. 1.1.2 Define scalar and vector quantities. 1.1.3 Solve problems of unit conversion.

1.2 Interpret data of measurement 1.2.1 Describe inaccuracy and errors in measurement 1.2.2 Apply techniques for measurement to ensure accurate data by using measurement equipments:-

a. Ruler b. Vernier Callipers c. Micrometer Screw Gauge

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PHYSICAL QUANTITIES & MEASUREMENTPHYSICAL QUANTITIES*

PHYSICAL QUANTITIES*

PHYSICAL QUANTITIESA quantity that can be measured.

A physical quantities have numerical value and unit of measurement.

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PHYSICAL QUANTITIES

BASE QUANTITIES*

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BASE QUANTITIESBase Quantities are physical quantities that cannot be derived from other physical quantities.Scientific measurement using SI units (International System Units). Table 1.1 Shows five base quantities and their respective SI units

Base QuantitiesSymbolSI UnitSymbol of SI unitLengthlmetermMassmkilogramkgTimetsecondsTemperatureTKelvinKElectric currentIampereA

PHYSICAL QUANTITIES

DERIVED QUANTITIES*

DERIVED QUANTITIIESDerived Quantities are physical quantities derived from combination of base quantities through multiplication or division or bothTable 1.2 shows some of the derived quantities and their respective derived units

Derived QuantitiesSymbolRelationship with base quantitiesDerived unitsAreaALength x Lengthm2VolumeVLength x Length x Lengthm3DensityMassLength x Length x Lengthkg/m3VelocityvDisplacementTimem/sAccelerationaVelocityTimem/s2ForceFMass x AccelerationNWorkWForce x DisplacementJEnergyEpEkMass x gravity x high @ x mass x velocity x velocityJPowerPForce x DisplacementTimeWPressurep ForceAreaN/m 2

DERIVED QUANTITIES

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PHYSICAL QUANTITIES

SCALAR & VECTOR QUANTITIES*

SCALAR AND VECTOR QUANTITIESSCALAR QUANTITIES

Physical quantities which have size (magnitude) but without specified direction.

VECTOR QUANTITIES

Physical quantities which have size (magnitude) and specified direction.

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DIFFERENTIATION BETWEEN SCALAR & VECTOR*

EXAMPLES OF SCALAR QUANTITIESMassTimeLengthTemperatureEnergyWorkSpeedPressure

*EXAMPLES OF VECTOR QUANTITIES DisplacementWeightForceVelocityAccelerationMomentum

Activity

Tick () the right answer for physical quantities below

QUANTITYSCALAR QUANTITYVECTOR QUANTITY5 m30 m/sec, East5 m, North20 degrees Celsius256 bytes

PHYSICAL QUANTITIES

PRIFIXES*

PREFIXESPrefixes are used to simplify the description of physical quantities that are either very big or very small.Table 1.4 Lists some commonly used SI prefixes

PrefixSymbolValueteraT1012gigaG109megaM106kilok103hektoh102dekada10desid10-1sentic10-2milim10-3mikroH10-6nanon10-9pikoP10-12

UNIT MEASUREMENT*

CONVERSION UNITSExample 1 : Convert 3.5 kilometer to meter.

Solution1km = 103m = 1000m

therefore 3.5 km = 3.5 km x 1000m 1 km = 3.5 1000 m = 3500 mIllustrates the usage of prefixes

Example 2:

Express 0.0005 Mg in g

Solution1kg = 103g = 1000g 1Mg = 106g = 1000 000g

therefore 0.005 Mg = 0.0005 Mg x 1000 000g 1 Mg = 0.0005 1000 000 g = 500 g

Convert the following into meters : 12km6.32km12cm220cm212mm1234mm*

PHYSICAL QUANTITIES

STANDART FORM*

*STANDARD FORMStandard form or scientific notation is used to express magnitude in a simpler way. In scientific notation, a numerical magnitude can be written as :

where 1 A < 10 and n is an integer

*STANDARD FORMExample 1 : For each of the following, express the magnitude using a scientific notation.The mean radius of the balloon = 100 mmThe mass of a butterfly = 0.0004 kg

Solution:

The mean radius of the balloon= 100 mm= 1.0 x 102 mm

The mass of a butterfly= 0.0004 kg= 4.0 x 10-4 kg

CONVERSION UNITSExample 2:

Convert 60mm2 to m2 .

Solution1 m = 1000 mm , 1m2 = 10002 m2

Therefore60 mm2 x 1 m2 = 60 x 10-6 m2 10002 mm2 Contoh 3:

Convert 0.075 kW to mW.

SolutionkW W mW

Therefore kW W = 0.075 kW 1000 W 1 kW = 0.075 1000 W = 75 W

W mW = 75 W 1000 mW 1 W = 75 000 mW

Example 4 : Change 60 km/j to m/s.

Solution 1 km = 1000m60 km/j = 60 km x 1000 m x 1 hr 1 hour = 60 minute 1 hr 1 km 3600 s 1 minute = 60 sec = 60 x 1000 m 3600 s = 16.67 m/s

Example 5 : The density of pure water is 1000 kg m-3, what is its density in g cm-3 ? Solution 1 kg = 1000 g 1 m = 100 cm

1000 kg = 1000 kg x 1000 g x ( 1 m x 1 m x 1 m ) m3 m3 1 kg 100 cm 100 cm 100 cm = 1000 x 1000 g 1 00 00 00 cm3 = 1 g cm-3

EXERCISES*Convert the following into squares meters:2500cm22.2 cm600 mm21510 mmConvert the following into cubic meters :

5200 mm112345 mm55 cm

EXERCISES*Complete the following unit conversion of speed. i. 820 kmh-1 = __________ ms-1ii. 1.36 ms-1 = __________ kmh-1iii. 18.12 ms-1 = __________ kmh-1iv. 970 kmh-1 = __________ ms-1

EXERCISES*Complete the following unit conversion of density and pressure. i. 7060 kgm-3 = __________ gcm-3ii. 123000 kgm-3 = __________ gcm-3iii. 2.45 gcm-3 = __________ kgm-3iv. 39800 Nm-2 = __________ Ncm-2v. 265x106 Nm-2 = __________ Ncm-2

Convert the following units

120 cm in unit meter (m)550 mg in unit gram (g)9.81 m/s in unit km/h8500 cm2 in m2908 g/cm3 in kg/m3 45 g/cm2 in kg/m2

MEASUREMENT

INSTRUMENT*

Micrometer screw gauge Vernier calipersMEASUREMENT INSTRUMENTSRuler

MEASUREMENT

VERNIER CALIPER*

*VERNIER CALIPER

HOW TO USE VERNIER CALIPER*

*HOW TO USE VERNIER CALIPER1.2.3.4

*10+60.25+= 16.25mm5.HOW TO USE VANIER CALIPER

*EXERCISES

MEASUREMENT

Micrometer Screw Gauge*

HOW TO USE MICROMETER SCREW GAUGE

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*How to Read the Reading? Reading = Reading of main scale + Reading of thimble scale. Reading of main scale = 0 - 25 mm Reading of thimble scale = 0 - 0.49mmReading of main scale = 5.5mm Reading of thimble scale = 0.28mm Actual Reading = 5.5mm + 0.28mm = 5.78mm

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MEASUREMENT

ERROR IN MEASUREMENT*

ERROR IN MEASUREMENTAn error is the difference between the measured value and the actual value.There are 2 main types of errors in measurement

Systematic errors

May be due to the error in calibration of instruments Zero error is due to non-zero reading when the actual reading should be zero

Random errors

Due to mistakes made by observer when taking measurement either through incorrect positioning of the eye (parallax) or the instruments when taking measurement

It may also occur when there is a sudden change of environmental factors like temperature, air circulation and lighting

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SYSTEMATIC ERRORS

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ZERO ERROR*

RANDOM ERRORS

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BIBLIOGRAFIhttp://spmphysics.onlinetuition.com.my/2012/04/physical-quantities.html

www.youtube.com

Internet source

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DBS 1012*DBS 1012*DBS 1012DBS 1012BB101 Engineering ScienceDBS 1012BB101 Engineering ScienceDBS 1012BB101 Engineering ScienceDBS 1012BB101 Engineering ScienceDBS 1012BB101 Engineering ScienceDBS 1012BB101 Engineering ScienceDBS 1012