1. Nature of Science Metric System- International System of Units (SI) (SI)

2. Learning Targets:  Use appropriate tools and equipment for measuring  Use the metric system for measuring  Use the “ladder method” and dimensional analysis to convert values between metric and English units

3. The Metric System The Metric System Standardized system of measurement used by all scientists worldwide Standardized system of measurement used by all scientists worldwide. Based on units of 10 Similar to our monetary system: 10 cents = dime 100 cents = dollar 10 dimes = dollar

4. Measurements are easily understood by all scientists Measurements are easily understood by all scientists Measurements are easier to convert than the English system Measurements are easier to convert than the English system Scientists use the SI System worldwide because: Why use the SI System? In the U.S. we use the English or Standard System, most of the rest of the world uses the Metric or SI System. The SI (International System of Units) system is the form of measurement typically used by scientists.

5. In the English system you have to remember so many units numbers... 12 inches in a foot 12 inches in a foot 3 feet in a yard 3 feet in a yard 5,280 feet in a mile 5,280 feet in a mile 16 ounces in a pound 16 ounces in a pound 4 quarts to a gallon 4 quarts to a gallon In the SI System you only have to remember one number - 10 and a few basic units

6. Basic Types of Measurement Length: measures distance between objects Mass: measures the amount of matter in an object Volume: measures the amount of space something takes up Temperature: measures molecular movement in an object in an object

7. Measurement System Comparisons All Measurement systems have standards. Standards are exact quantities that everyone agrees to use as a basis of comparison. MEASUREMENT BASIC UNIT ABBREVIATION LENGTHMeterm VOLUMELiterL TEMPERATURECelsius°C MASSGramg TIMESecond s, sec

8. 1 Liter 1 Meter1 Gram

9. Weight vs. Mass Weight vs. Mass Measure of the force of gravity on an object Measure of amount of matter in an object NOT affected by gravity

10. Length is the distance between two points. Does not matter if it is width, height, depth, etc. All are length measurements. Does not matter if it is width, height, depth, etc. All are length measurements. The basic unit of length in the SI System is the meter. The basic unit of length in the SI System is the meter. The meter is about the length of the English yard (3 feet). The meter is about the length of the English yard (3 feet). Area is a variation of a length measurement. Area is a variation of a length measurement.  Area is length x width.  Expressed in units 2 (m 2, cm 2, mm 2 etc.) Metric Measurement: Length

11. Metric Measurement: Volume Volume is a measurement of the amount of space something takes up. The basic unit used for volume is the liter. This unit is used for the volumes of liquids. The basic unit used for volume is the liter. This unit is used for the volumes of liquids. Volumes of solids are figured using this formula: Volumes of solids are figured using this formula: (L)ength x (W)idth x (H)eight cm x cm x cm = cm 3 Objects without a definite length, width or height (a rock for example), can use water displacement to determine volume. NOTE: 1 ml = 1 cm 3 Objects without a definite length, width or height (a rock for example), can use water displacement to determine volume. NOTE: 1 ml = 1 cm 3

12. Weight vs. Mass Weight vs. Mass Weight and Mass are related, but NOT the same.  Weight can change depending on location  Mass is constant regardless of location  The greater the mass, the larger the pull of gravity. The larger the pull of gravity, the greater the weight The larger the pull of gravity, the greater the weight

13. Metric Measurement: Temperature Temperature is a measure of the kinetic energy of the atoms in an object. Temperature is measured with a thermometer and measured in Celsius or Kelvin. Temperature is measured with a thermometer and measured in Celsius or Kelvin. Celsius ranges from 0 (freezing) to 100 (boiling). Celsius ranges from 0 (freezing) to 100 (boiling). The Kelvin scale begins at absolute zero, or 0 K. At 0 Kelvin no more heat can be removed from an object. The Kelvin scale begins at absolute zero, or 0 K. At 0 Kelvin no more heat can be removed from an object.  To convert to Kelvin you add 273 degrees to the Celsius reading.  Freezing in Kelvin is 273 K, boiling is 373 K.

14. Density – how much mass is packed into a certain volume of a substance

15. Formula for Density for regular shaped objects D = M/V M = mass (use triple beam balance) V = Volume (liquids - use graduated cylinder) (cube – s x s x s) (rectangle – l x w x h)

16. Density for irregular shaped objects: Use displacement method 1. put water in a graduated cylinder 2. measure the volume 3. put object in graduated cylinder 4. measure the new volume. 5. subtract the old volume from the new volume. It equals the object’s volume.