Chapter 1 Measurement
What is Physics?
Study of matter and energy.
What is Physics Quantities?
Quantity that can be measured by numerical value and unit.
(a)→ Base Quantities
Physical quantities that cannot be derived from in terms of other quantities.
Base Quantities Quantities Symbol SI Unit Symbol of SI unit
Length ℓ Metre m
Time t Seconds s
Mass m Kilogram kg
Temperature T Kelvin K
Electric current I Ampere A
Luminous intensity Iv Candela cd
Amount of n Mole mol
substances
→ Derived Quantities
Physical quantities that derived from combination base quantities through “ x or /” or both.
(b)→ Scalar Quantities
Have magnitude only
Ex: length, distance, speed
→ Vector Quantities
Have magnitude and direction
Ex: momentum, velocity, force, displacement
,Prefixes
+ x 10^ -
Exa,E 18 Atto,a
Peta,P 15 Fento,f
Tera,T 12 Pico,p
Giga,G 9 Nano,n
Mega,M 6 Micro,µ
Kilo,k 3 Milli,m
Hector,h 2 Centi,c
Deca,da 1 Deci,d
, Graph
Relation: y directly proportional to x.
Relation: y increases linearly to x.
Relation: y decreases linearly to x.
What is Physics?
Study of matter and energy.
What is Physics Quantities?
Quantity that can be measured by numerical value and unit.
(a)→ Base Quantities
Physical quantities that cannot be derived from in terms of other quantities.
Base Quantities Quantities Symbol SI Unit Symbol of SI unit
Length ℓ Metre m
Time t Seconds s
Mass m Kilogram kg
Temperature T Kelvin K
Electric current I Ampere A
Luminous intensity Iv Candela cd
Amount of n Mole mol
substances
→ Derived Quantities
Physical quantities that derived from combination base quantities through “ x or /” or both.
(b)→ Scalar Quantities
Have magnitude only
Ex: length, distance, speed
→ Vector Quantities
Have magnitude and direction
Ex: momentum, velocity, force, displacement
,Prefixes
+ x 10^ -
Exa,E 18 Atto,a
Peta,P 15 Fento,f
Tera,T 12 Pico,p
Giga,G 9 Nano,n
Mega,M 6 Micro,µ
Kilo,k 3 Milli,m
Hector,h 2 Centi,c
Deca,da 1 Deci,d
, Graph
Relation: y directly proportional to x.
Relation: y increases linearly to x.
Relation: y decreases linearly to x.