2.1  Physical quantities and units

 

2.1.1  Physical quantities

 

 

Learners should be able to demonstrate and apply their knowledge and understanding of:

 

(a) physical quantities have a numerical value and a unit

Every thing in Physics has a value and a unit.  If you do not quote the units, the numbers are completely meaningless.  You should already know most of the required units.  If not, lots of links in the sections below.  It matters whether you use a capital or lower case letter so pay attention.

 

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(b) making estimates of physical quantities listed in this specification.

 

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2.1.2  S.I. Units

Learners should be able to demonstrate and apply their knowledge and understanding of:

 

(a) Système Internationale (S.I.) base quantities and their units – mass (kg), length (m), time (s), current (A), temperature (K), amount of substance (mol)

 

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(b) derived units of S.I. base units Examples: momentum kg m s-1 and density kg m–3

 

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(c) units listed in this specification

 

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(d) checking the homogeneity of physical equations using S.I. base units

 

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(e) prefixes and their symbols to indicate decimal submultiples or multiples of units – pico (p), nano (n), micro (μ), milli (m), centi (c), deci (d), kilo (k), mega (M), giga (G), tera (T) As set out in the ASE publication Signs, Symbols and Systematics (The ASE Companion to 16–19 Science, 2000).

 

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(f) the conventions used for labelling graph axes and table columns.

 

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