𝐹𝑃𝑆
[𝑀0 𝐿𝑇 −2 ]
Welcome to 𝑘𝑔
NOTES
Physical world and
Units & Measurements
𝑚𝑜𝑙
𝐶𝐺𝑆
𝑀𝐾𝑆
, Physical Quantities
• Represent Quantities from Physical World.
• They should be measurable directly or indirectly by an instrument.
• Can be expressed by a numerical value followed by a unit.
𝑃𝑄 = 𝑛 × 𝑢
Which of these are physical quantities ?
1. The density of brass is 8.4 𝑔Τ𝑐𝑚3
2. The relative density of alcohol is 0.8
3. The mass of an empty bottle is 21.8 𝑔
4. The velocity of a moving train is 50 𝑘𝑚Τℎ
A B
1 and 4 1, 3 and 4
C D
1, 2, 3 and 4 1, 2 and 3
, Unit
Unit is a reference standard used to compare and measure a physical quantity.
𝑢
unit
System of units Mass – Length – Time
CGS centimetre – gram – second
FPS foot – pound – second
MKS meter – kilogram – second
, Unit
Prefixes Factor Prefixes Factor
yotta 1024 centi 10−2
zetta 1021 milli 10−3
exa 1018 micro 10−6
peta 1015 nano 10−9
tera 1012 pico 10−12
giga 109 femto 10−15
mega 106 atto 10−18
kilo 103 zepto 10−21
deci 10−1 yocto 10−24
[𝑀0 𝐿𝑇 −2 ]
Welcome to 𝑘𝑔
NOTES
Physical world and
Units & Measurements
𝑚𝑜𝑙
𝐶𝐺𝑆
𝑀𝐾𝑆
, Physical Quantities
• Represent Quantities from Physical World.
• They should be measurable directly or indirectly by an instrument.
• Can be expressed by a numerical value followed by a unit.
𝑃𝑄 = 𝑛 × 𝑢
Which of these are physical quantities ?
1. The density of brass is 8.4 𝑔Τ𝑐𝑚3
2. The relative density of alcohol is 0.8
3. The mass of an empty bottle is 21.8 𝑔
4. The velocity of a moving train is 50 𝑘𝑚Τℎ
A B
1 and 4 1, 3 and 4
C D
1, 2, 3 and 4 1, 2 and 3
, Unit
Unit is a reference standard used to compare and measure a physical quantity.
𝑢
unit
System of units Mass – Length – Time
CGS centimetre – gram – second
FPS foot – pound – second
MKS meter – kilogram – second
, Unit
Prefixes Factor Prefixes Factor
yotta 1024 centi 10−2
zetta 1021 milli 10−3
exa 1018 micro 10−6
peta 1015 nano 10−9
tera 1012 pico 10−12
giga 109 femto 10−15
mega 106 atto 10−18
kilo 103 zepto 10−21
deci 10−1 yocto 10−24
