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Metric System Basics. Only a few areas of the world still use the English measurement system U.S. Myanmar Liberia. Problems. Metric mishap caused loss of NASA orbiter September 30, 1999 CNN
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Metric System Basics • Only a few areas of the world still use the English measurement system • U.S. • Myanmar • Liberia
Problems • Metric mishap caused loss of NASA orbiter • September 30, 1999 CNN • NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while NASAs team used the metric system for a key spacecraft operation. • The units mismatch prevented navigation information from transferring between the Mars Climate Orbiter spacecraft team in at Lockheed Martin in Denver and the flight team at NASAs Jet Propulsion Laboratory in Pasadena, California. • Lockheed Martin helped build, develop and operate the spacecraft for NASA. Its engineers provided navigation commands for Climate Orbiters thrusters in English units although NASA has been using the metric system predominantly since at least 1990.
Metric (SI) vs. American Measurements • Metric (SI) System • Grams • Meters • Liters • Celsius • http://en.wikipedia.org/wiki/United_States_customary_units • American System • Pounds • Ounces • Feet • Inches • Yards • Miles • Gallons • Cups • Teaspoon • Quarts • Pints • Fahrenheit
Metric System Basics Most of the world uses the metric system (95%) • Why use the metric system? 1. To have a single unit for every physical quantity 2. MUCH EASIER: Based on units of 10
Metric System Basics • The metric system is based on a base unit that corresponds with a certain type of measurement • Length = meters (m) • Volume = liters (L) • Mass or weight = grams (g)
Prefixes • k: kilo = 1 thousand base units (x1000) • h: hecto = 1 hundred base units (x100) • D: deca = ten base units (x10) • d: deci = 1 tenth of a base unit (÷10) • c: centi = 1 hundredth of a base unit (÷100) • m: milli = 1 thousandth of a base unit (÷1000)
Metric Olympics Categories • Frisbee Toss (meters) • Guess your partner’s weight (in kg ) • Bean grab (grams) • Volume guess (milliliters) • Ball Roll (meters) • Popsicle Stick Flip (meters)
Measuring Volume • Volume: the amount of space occupied by an object • Rectangle: length x width x height • LiquidVolume: 1 liter = decimeter cubed (dm³)
Measuring Matter • Density: a measure of how tightly packed molecules are in an object • d = mass / volume
Measuring Temperature • Temperature: a measure of how hot or cold something is • Celsius Scale • Freezing point of water is 0º C • Boiling Point of water is 100º C • Kelvin Scale (SI unit of temperature) • Usually used in astronomy • Absolute Zero (0K) = -273 K: the coldest possible temperature