UNIT II.2 & II.3 PPTSI UNITS & METRIC CONVERSIONS

II.2 SI UNITS

SI = International system of metric units.

Base unit = basic unit of measurement (all other units are multiples of base units or

combinations)

1. BASE UNITS length = metre (m) mass = gram (g) time = seconds (s) amount of substance = mole (mol)

II.2 SI UNITS

2. MULTIPLES OF BASE UNITS kilo = k (103) centi = c (10-2) milli = m (10-3)

**Table on page 17 – KNOW**

3. IMPORTANT EQUIVALENCES 1 mL = 1 cm3

1 m3 = 103 L 1 t = 103 kg

II.2 SI UNITS

Example: Re-write the expression “6 kilograms” using

PREFIX and UNIT SYMBOLS an EXPONENTIAL EQUIVALENT

The prefix symbol that stands for kilo is ___ and the unit symbol that stands for grams is ___

6 kilograms =

The exponential equivalent to kilo is ____ 6 kilograms = Questions: p.19 #11-14

II.3 METRIC CONVERSIONS

Metric conversions involve using unit conversions between prefix symbols and exponential equivalents.

Example: Write a conversion statement between cs

and s. ‘c’ stands for _____ then

Questions: p.19 #15 (odds)

II.3 METRIC CONVERSIONS

Example: How many millimeters are in 5 km?

Unknown amount = Initial amount = Conversion factors =  Combine conversion factors to make

connection:

Solution

II.3 METRIC CONVERSIONS

Diagram (p. 20) – how prefix symbols relate to a central base unit:

II.3 METRIC CONVERSIONS

Example 1: Express 7µm in Megametres.

Example 2: (p.21 #16e) If 1 dL = 10-1 L and 1 kL = 103 L, how many

decilitres in 0.5kL?

II.3 METRIC CONVERSIONS Questions: p. 21 #16,17,18,24,28

DERIVED QUANTITIES  Derived quantity =   Derived unit =

Example on p. 23

Question: p. 21 #29

II.3 METRIC CONVERSIONS

Example 3: Convert 1cg/ mL into dg/L

Unknown: Initial: Conversion factors =

Solution:

ASSIGNMENT