1.2 base derived quantities

1. 1.2 Base & Derived Quantities1.2 Base & Derived Quantities
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Chapter 1 Chapter 1
Introduction To PhysicsIntroduction To Physics

2. Learning OutcomesLearning Outcomes
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4. PHYSICAL QUANTITYPHYSICAL QUANTITY
Wow! Is this
real??!
Hehehe….
Can u guess
what is my
height?
Weight Mass Time
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5. PHYSICAL QUANTITYPHYSICAL QUANTITY
The quantity that The quantity that can be measuredcan be measured
Measurable :Measurable :
The process of determining the The process of determining the
value of a quantity using a scientific value of a quantity using a scientific
instrument with a standard scaleinstrument with a standard scale
Example:Example:
Mass, weight, height, time, Mass, weight, height, time,
temperaturetemperature
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6. Length of meter ruler = 100.0 cmLength of meter ruler = 100.0 cm
Which isWhich is
1. Physical quantity?1. Physical quantity?
2. Numerical value?2. Numerical value?
3. Unit of measurement?3. Unit of measurement?
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7. Non-physical QuantityNon-physical Quantity
The quantity that The quantity that cannot be cannot be
measuredmeasured..
Example:Example:
Feelings-happy Feelings-happy , sad , sad , ,
angry ….angry ….
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8. Physical Quantities
Base Quantities Derived Quantities
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9. Base QuantityBase Quantity Derived QuantityDerived Quantity
Physical quantities Physical quantities
that that cannot be cannot be
defineddefined in terms of in terms of
other other physical physical
quantitiesquantities
Physical quantities Physical quantities
derived from base derived from base
quantitiesquantities by by
multiplication or multiplication or
division or bothdivision or both
Length, Mass, Length, Mass,
Time, Time,
Temperature, Temperature,
Electric CurrentElectric Current
Density, Pressure, Density, Pressure,
Force….Force….
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10. Base QuantitiesBase Quantities
Physical quantities that cannot be defined Physical quantities that cannot be defined
in terms of other physical quantities.in terms of other physical quantities.
Unit : base unitUnit : base unit
Name & SymbolName & Symbol S.I. Unit & SymbolS.I. Unit & Symbol
Length / lLength / l meter / m meter / m
Mass / mMass / m kilogram / kgkilogram / kg
Time / tTime / t second / ssecond / s
Temperature / TTemperature / T kelvin / Kkelvin / K
Electric Current / Electric Current / II ampere / Aampere / A
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12. Derived QuantitiesDerived Quantities
Physical quantities derived from base Physical quantities derived from base
quantity (multiplication or division or both)quantity (multiplication or division or both)
Unit : Derived UnitUnit : Derived Unit
Name & SymbolName & SymbolS.I. Unit & SymbolS.I. Unit & Symbol
Velocity / vVelocity / v meter per second / msmeter per second / ms
-1-1

Force / FForce / F Newton / NNewton / N
Pressure / PPressure / P Pascal / PaPascal / Pa
Weight / WWeight / W Newton / NNewton / N
Density / Density / ρρ kg mkg m
-3 -3
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13. DERIVED QUANTITIESDERIVED QUANTITIES
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14. (a) Show the relationship between (a) Show the relationship between
the following derived quantities and the following derived quantities and
their corresponding base quantities.their corresponding base quantities.
(b) Derive the units for the following (b) Derive the units for the following
physical quantitiesphysical quantities
Density Density = mass / volume= mass / volume
= mass / (length)= mass / (length)
33
= kg m= kg m
-3-3
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15. PrefixPrefix SymbolSymbol ValueValue
TeraTera TT 1010
1212
GigaGiga GG 1010
99
MegaMega MM 1010
66
KiloKilo k k 1010
33
HectoHecto h h 1010
22
DecaDeca dada 1010
11
DeciDeci d d 1010
-1-1
CentiCenti cmcm 1010
-2-2
MilliMilli mm 1010
-3-3
MicroMicro ųų 1010
-6-6
NanoNano nn 1010
-9-9
picopico pp 1010
-12-12

16. 4amanah 10jan until here4amanah 10jan until here
Ask them to memorise prefixes follow text Ask them to memorise prefixes follow text
bookbook
Ask to collect rm1 by next weekAsk to collect rm1 by next week
30 students30 students
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19. Changing UnitChanging Unit
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20. PrefixPrefix ValueValue
Tera / TTera / T 1010
1212
Giga / GGiga / G1010
99
Mega / MMega / M1010
66
Kilo / kKilo / k1010
33
Hecto / hHecto / h1010
22
Deca /daDeca /da1010
11
Deci / dDeci / d1010
-1-1
Centi/cmCenti/cm1010
-2-2
Milli / mMilli / m1010
-3-3
Micro / Micro / ųų1010
-6-6
Nano / nNano / n1010
-9-9
Pico / pPico / p1010
-12-12
10
-6-(3)
=10
-9
1.23 ųmųm
= 1.23 x 10
-6-(3)
km
= 1.23 x 10
-9
km
10
(A) -(B)
A = initial prefix
B = final prefix
1.23 ųm ųm = _____ km
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21. PrefixPrefix ValueValue
Tera / TTera / T 1010
1212
Giga / GGiga / G1010
99
Mega / MMega / M1010
66
Kilo / kKilo / k1010
33
Hecto / hHecto / h1010
22
Deca /daDeca /da1010
11
Deci / dDeci / d1010
-1-1
Centi/cmCenti/cm1010
-2-2
Milli / mMilli / m1010
-3-3
Micro / Micro / ųų1010
-6-6
Nano / nNano / n1010
-9-9
Pico / pPico / p1010
-12-12
10
6-(-9)
= 10
15
4.56 Mg
= 4.56 x 10
6-(-9)

= 4.56 x 10
15
ng
4.56 Mg = _____ ng
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23. Change to S.I. UnitChange to S.I. Unit
456 g/cm456 g/cm
33
= = 456 g456 g
cmcm
33
= = 456 x 10456 x 10
-3 -3
kgkg
1 x (101 x (10
-2-2
m) m)
33

= = 456 x 10456 x 10
-3 -3
kgkg
1 x 101 x 10
-6-6
m m
33

=456 x 10=456 x 10
-3 -3
x 10x 10
66
kg m kg m
-3 -3
= 456 x 10= 456 x 10
33
kg m kg m
-3 -3
= 4.56 x 10= 4.56 x 10
55
kg m kg m
-3-3
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24. Exercise 1Exercise 1
January 2011January 2011
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25. For the following physical quantities, For the following physical quantities,
derive theirderive their
i) base quantitiesi) base quantities
ii) units ii) units
(a)(a)VelocityVelocity
(b)(b)AccelerationAcceleration
(c)(c)ForceForce
(d)(d)WorkWork
(e)(e)DensityDensity
1
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26. Derived
Quantities
Base Quantities Units
a)Velocity displacement/time
= length/time
m/s
b) Acceleration
c) Force
d) Work
e) Density
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27. (a) Velocity(a) Velocity
= displacement/time= displacement/time
= length/time= length/time
= m/s= m/s
= m s= m s
-1-1
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28. (b) Acceleration(b) Acceleration
= = Change in VelocityChange in Velocity
timetime
= = lengthlength
(time)(time)
22
==m/sm/s
22
==m sm s
-2-2
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29. (c) Force(c) Force
= mass x acceleration= mass x acceleration
= mass x = mass x lengthlength
(time)(time)
22
= kg m s= kg m s
-2-2
= Newton= Newton
= N = N

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30. (d) Work(d) Work
= Force x Displacement= Force x Displacement
= mass x acceleration x length= mass x acceleration x length
= mass x = mass x lengthlength x length x length
(time)(time)
22
==
kg m kg m
22
s s
-2-2
= Nm = J= Nm = J
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31. e) Densitye) Density
= = massmass
volumevolume
= = massmass
(length)(length)
33
= kg m= kg m
-3-3
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32. Derived
Quantities
Base Quantities Units
a)Velocity displacement/time
= length/time
m/s
b) AccelerationChange in
Velocity/time
= length/(time)
2
m/s
-2
c) Force Mass x acceleration
= (mass)(length)
(time)
2
d) Work Force x
displacement
=
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33. Show the relationship between Show the relationship between
the following derived the following derived
quantities and their quantities and their
corresponding base corresponding base
quantities.quantities.
(a) acceleration(a) acceleration
(b) momentum(b) momentum
2
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36. 3
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