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Chapter1 Units, Physical Quantities, NG HUI YUN A20SC0187 - Coggle…
Chapter1
Units, Physical Quantities
Models
Laws
Theories
Principles
Estimated Uncertainty
Percent Uncertainty
Significant Figures
no. of sf in final answer is same as that of primary data with least sf
Scientific Notation
x 10^n
Accuracy VS Precision
Accuracy-Closeness of measurements to a specific value
Precision-Closeness of measurements to each other (Consistency)
Units, Standards & the SI System
7 Basic Units in SI System
Length, metre(m)
Mass, kilogram(kg)
Time, second(s)
Temperature, Kelvin(K)
Current, Ampere(A)
Amount of Substance, mole(mol)
Luminous Intensity, candela(cd)
Unit Conversion
Example:
1m=100cm
1=100cm/m
3.5m=2.5mx1
2.5m=2.5mx100cm/m
2.5m=250cm
SI Prefixes
Order of Magnitude
Rapid Estimating
For rapid estimating, round off all numbers to 1sf and calculate
Dimensions & Dimensional Analysis
Dimensions Example:
length [L]
mass [M]
time [T]
a=b+c
a, b and c must have same dimensions
NG HUI YUN
A20SC0187
