Bell RingerBell Ringer1.1. (3.67 x 10(3.67 x 1088) (9.5 x 10) (9.5 x 1055))

2.2. (6.236 x 10(6.236 x 10-7-7) ) / / (1.45 x 10(1.45 x 1022))

3.3. (9.8 x 10(9.8 x 1055) (4.66 x 10) (4.66 x 1033))

4.4. (8 x 10(8 x 10-4-4) (5.847 x 10) (5.847 x 10-6-6))

5.5. (2.25 x 10(2.25 x 1077) ) // (4.5 x 10 (4.5 x 10-2-2))

Check your Significant Figures!Check your Significant Figures!

Dimensional AnalysisDimensional Analysis

SI UnitsSI Units Metric SystemMetric System

What units do scientists use What units do scientists use for their measurements? for their measurements?

SI Units of Measurement

What units do scientists use What units do scientists use for their measurements? for their measurements?

SI Units of Measurement

Base Units and Derived Units Base Units and Derived Units SI is built upon 7 metric units, known SI is built upon 7 metric units, known as base units. as base units.

Seven metric base units make up the Seven metric base units make up the foundation of SI.foundation of SI.

SI Units of Measurement

Temperature Scales:Temperature Scales:

Celsius ScaleCelsius Scale Fahrenheit Fahrenheit Scale Scale

Measuring Temperature

The SI base unit for temperature is the The SI base unit for temperature is the kelvin (K). kelvin (K).

• A temperature of 0 K, or 0 kelvin, refers to A temperature of 0 K, or 0 kelvin, refers to the lowest possible temperature that can the lowest possible temperature that can be reached. be reached.

Measuring Temperature

Specific combinations of SI base units yield Specific combinations of SI base units yield derived units. derived units.

SI Units of Measurement

Metric Prefixes Metric Prefixes The metric unit is not always a convenient one The metric unit is not always a convenient one to use. A metric prefix indicates how many to use. A metric prefix indicates how many times a unit should be multiplied or divided by times a unit should be multiplied or divided by 10. 10.

109 106 103 102 101   

BASE

10-1 10-2 10-3 10-6 10-9

 Giga 

Mega Kilo Hecto Deca deci centi milli micro nano

G M k h da d c m µ n

  

                 

                       

Metric System Prefix Metric System Prefix ChartChart

For example, the time it takes for a computer For example, the time it takes for a computer hard drive to read or write data is in the hard drive to read or write data is in the range of thousandths of a second, such as range of thousandths of a second, such as 0.009 second. Using the prefix 0.009 second. Using the prefix milli- milli- (m), you (m), you can write 0.009 second as 9 milliseconds, or 9 can write 0.009 second as 9 milliseconds, or 9 ms. ms.

SI Units of Measurement

Metric prefixes can also make a unit larger. Metric prefixes can also make a unit larger. For example, a distance of 12,000 meters can For example, a distance of 12,000 meters can also be written as 12 kilometers. also be written as 12 kilometers.

Metric prefixes turn up in nonmetric units as Metric prefixes turn up in nonmetric units as well. If you work with computers, you well. If you work with computers, you probably know that a gigabyte of data refers probably know that a gigabyte of data refers to 1,000,000,000 bytes. A megapixel is to 1,000,000,000 bytes. A megapixel is 1,000,000 pixels.1,000,000 pixels.

SI Units of Measurement

SI Units of Measurement

SI Units of Measurement