2. Units of Measurement

3. Understanding Units Does anyone know what the high temperature is going to be today? What unit of measure do we commonly use for temperature in the US. Although Fahrenheit is the unit of measure we commonly hear, we will always use the International System of Units or SI. Does anyone know the SI unit of measure for temperature? (Kelvin) Does anyone know what the high temperature is going to be today? What unit of measure do we commonly use for temperature in the US. Although Fahrenheit is the unit of measure we commonly hear, we will always use the International System of Units or SI. Does anyone know the SI unit of measure for temperature? (Kelvin) Units are very important. When you are completing a problem, doing a lab, taking a test, it is imperative that you not only pay attention to the numbers, but also to the units. Units are very important. When you are completing a problem, doing a lab, taking a test, it is imperative that you not only pay attention to the numbers, but also to the units. The SI base units: mass, length, temp, etc. Then there are derived units. The SI unit for area is (m 2 ). Note that because the SI unit for length is m, it follows that the area is m 2. What is the SI unit for volume? (cubic meters). Density is m/v, so kg/m 3. The SI base units: mass, length, temp, etc. Then there are derived units. The SI unit for area is (m 2 ). Note that because the SI unit for length is m, it follows that the area is m 2. What is the SI unit for volume? (cubic meters). Density is m/v, so kg/m 3. The next two slides show the SI base units and derived units respectively. The next two slides show the SI base units and derived units respectively.

4. SI Base Units QuantityUnitSymbol LengthMeterm MassKilogramkg TemperatureKelvinK TimeSeconds Electric Current ampereA

5. Derived Units QuantityUnitSymbol Area Square meter m2m2m2m2 Volume Cubic meter m3m3m3m3 Density Kilograms per cubic meter Kg/m 3 Pressure Pascal (kg/ms 2 ) Pa Energy Joule (kgm 2 /s 2 ) J Electric Charge coulombC

6. Instruments for Measuring

7. Metric Prefixes We can use the prefixes as a convenient way to write numbers. The prefix tells us how many times the number is multiplied or divided by 10. We can use the prefixes as a convenient way to write numbers. The prefix tells us how many times the number is multiplied or divided by 10. Often times we will want to convert from one unit of measurement to the another. Often times we will want to convert from one unit of measurement to the another. Example: Height of Mt. Everest is 8848 m, how may km is this? We will need to know that the prefix kilo is 1000 so 1 km = 1000 m Example: Height of Mt. Everest is 8848 m, how may km is this? We will need to know that the prefix kilo is 1000 so 1 km = 1000 m 8848 m x 1 km = 8848 km = 8.848 km 1000 m 1000 1000 m 1000

8. PrefixSymbolMeaningEquality gigaG Billion (10 ^9) 1 billion bytes = 1 gigabyte megaM Million (10^ 6) 1 million bytes = 1 megabyte kilok Thousand (10^ 3) 1000 meters= 1 kilometer decid Tenth (10^ -1) 1 meter = 10 decimeter centic Hundreth (10^ - 2) 1 meter = 100 centimeters millimThousandth (10^ -3) (10^ -3) 1 meter = 1000 millimeters micro Millionth (10^ -6) 1 meter = million micrometers nanon Billionth (10 ^-9) 1 meter = billion nanometers