Mathematics and Physics
SI: System International d'States
The worldwide scientific adaption of metric systems
Mass: Kilogram: kg
Time: Second: s
Length: Meter: m
Temperature: Kelvin: K
Amount of substance: Mole: mol
Electric Current: Ampere: A
Luminous Intensity: Candela: cd
Any other metric systems are called derived units: for example Volume: Liters: L
Prefixes
Tera: 10^12
Are used to change SI base units to powers of 10
Giga: 10^9
Mega: 10^6
Kilo 10^3
Hecto: 10^2
Deka: 10^1
Base
Deci: 10^-1
Centi: 10^-2
Milli: 10^-3
Micr: 10^-6
Nano: 10^-9
Pico: 10^-12
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Converting Examples
Steps
Then decide if you'll divide or multiply
Then choose your exponent according to the prefix
Is the conversion from bigger to smaller or the opposite?
Scientific Notation
a mathematical expression used to represent a decimal number between 1 and 10 multiplied by ten, so you can write large numbers using less digits.
Dimensional Analysis
A method of treating the units as algebraic quantities, which can be cancelled. They can be used for:
Check that you have set up a problem correctly
Check that your answer is in correct units
Choose conversion factors
Significant Figures
All measurements are approximate and have significant figures. The last digit given for any measurement is the uncertain digit.
Significant figures are the valid digit in a measurement. .
The number of significant figures depends on the precision of the measuring device
Rules of Sig Figs
Zeros between non-zero digits are significant: 102, 2005,
Leading zeros are never significant: 0.02, 001.887
All non-zero digits are significant: 1, 2, 3, 4, 5, 6, 7, 8, 9.
Final zeros after a decimal point are significant: 389,000; 2.02000;
Zeros used on the right with no decimal points are not significant: 100 has only 1 significant figures
Significant Figures
Multiplying and Dividing
Adding and Subtracting
If you add or subtract, the answer is rounded to the same number of decimal places as the measurement with the least number of decimal places.
Answer will have the same number of decimal places as the least measurement used (least number of decimals).
Multiplication and division of sig figs – your answer must be equal to the measurement with the least number of sig figs.
Answer will be rounded to the same number of significant figures as the component with the fewest number of significant figures.
WORK BY:
RAFAA BUKHARY