The Metric System Conversions Measurement Significant Digits Graphing CHAPTER 2 The Metric System Conversions Measurement Significant Digits Graphing

Measure The Room Lab Measure the length and width of the room in “shoe” units. Discuss differences. Why doe we use standards? Name US units volume, distance, …etc Name Metric “Base” units. Name Metric prefixes Place prefixes in order smallest to largest.

2.1 The Metric System and SI Why use the Metric System Based on powers of 10, convenient to use The Syste’me Interationale d’Unite’s = SI = The Metric System This is the standard system used throughout the world by scientists, engineers, and everyone else everywhere except US.

Metric Prefixes Name as many metric prefixes as you can Now place them in order from smallest to largest Give students correct order

Why don’t we use the Metric System in the United States? Good question.

Base Units Length = meter (m) Mass = gram (g) → “standard” unit = kg Volume = liter (l) Time = second (s) Temperature = Kelvin (K) Amount of a substance = mole (mol) …etc

Definition of a kilogram The mass of a small platinum-iridium metal cylinder kept at a very controlled temperature and humidity.

Definition of a meter The distance traveled by light in a vacuum during a time interval of 1/299 792 458 seconds.

Definition of a second The fraquency of one type of radiation emitted by a cesium-133 atom.

SI Prefixes Giga – G 109 1 000 000 000 Mega –M 106 1 000 000 kilo – k 103 1000 hecto – h 102 100 deka – da 10 10 BASE UNIT meters/liters/grams/…etc deci – d 10-1 0.1 centi – c 10-2 0.01 milli – m 10-3 0.001 micro – μ 10-6 0.000 001 nano – n 10-9 0.000 000 001 pico – p 10-12 0.000 000 000 001

Introduction to meter stick Meter (m) – dm – cm – mm Demonstration with meter sticks #1, #2, #3, plus standard meter stick.

METRIC “STEP” SYSTEM & CONVERSIONS Convert 102m → mm 102m = 102 000mm Convert 427 693μm → m 427 693μm = 0.427 693m Metric Conversion Hand Out #1

Handout #1

METRIC “Step System” μ m c p m c p m c p G M k da h d n G M k da h d n BASE d m c n p G M k da h BASE d m c n p G M k da h BASE d m c n p For each step you go up, move the decimal point one place to the left. For each step you go down, move the decimal point one place to the right. μ

Handout #2 Handout Metric Conversion Quiz 17-points (OPTIONAL) Handout Metric Conversion Worksheet 1-24 (OPTIONAL)

Conversions Cont. Length 1 inch = 2.54 cm (exactly) Volume 1 liter = 1.0576 qt Mass 1 kg = 2.21 lbs Weight 1 lb = 4.45N (Newtons) More useful conversions on back cover of text book

Dimensional Analysis Method = Factor Label Method Example #1 4km → in 4km x 1000m x 100cm x 1in = 1 1km 1m 2.54cm 157 480in

Example #2 26dam → yds 26dam x 1000cm x 1in x 1ft x 1yd = 1 1dam 2.54cm 12in 3ft 284.3yds

More Example Problems 3) 37hl → gal 37hl = 978.28gal 4) 439 672 107mg → tons 439 672 107mg = 0.4858tons

5) 467 223 921 732 oz → Gg 467 223 921 732 oz = 13,269.16Gg 6) 937 456 737mg → tons 937 456 737mg = 1.03tons Hint: Insert the units first to ensure that the units will cancel out leaving only the unit that you want to end up with.

Additional Handouts Handout #3 Handout#4 Handout#5 Handout – Conversion Handout-1