1 / 41

Preview

Section 2 Units of Measurement. Chapter 2. Preview. Objectives Units of Measurement SI Measurement SI Base Units Derived SI Units Conversion Factors. Chapter 2 Vocabulary. 6. quantity 7. SI 8. weight 9. derived unit 10. volume 11. density 12. conversion factor

jscheer
Download Presentation

Preview

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Section2 Units of Measurement Chapter 2 Preview • Objectives • Units of Measurement • SI Measurement • SI Base Units • Derived SI Units • Conversion Factors

  2. Chapter 2 Vocabulary • 6. quantity • 7. SI • 8. weight • 9. derived unit • 10. volume • 11. density • 12. conversion factor • 13. dimensional analysis

  3. Chapter 2 • Geez.. get with program Liberia and Myanmar

  4. Section2 Units of Measurement Chapter 2 Objectives • Distinguish between a quantity, a unit, and a measurement standard. • Name and use SI units for length, mass, time, volume, and density. • Distinguish between mass and weight. • Perform density calculations. • Transform a statement of equality into a conversion factor.

  5. Section2 Units of Measurement Chapter 2 Units of Measurement • Measurements represent quantities. • A quantity is something that has magnitude, size, or amount. • measurement  quantity • the teaspoon is a unit of measurement • volume is a quantity • The choice of unit depends on the quantity being measured.

  6. Section2 Units of Measurement Chapter 2 SI Measurement • Scientists all over the world have agreed on a single measurement system called Le Système International d’Unités, abbreviated SI. • SI has seven base units • most other units are derived from these seven

  7. Section2 Units of Measurement Chapter 2 C. SI Base Units

  8. C. SI base Units *All other units are derived units

  9. 2.2 The International System of Units (SI)

  10. D. SI Prefixes

  11. D. SI prefixes

  12. Section2 Units of Measurement Chapter 2 SI Base Units Mass • Mass is a measure of the quantity of matter. • The SI standard unit for mass is the kilogram. • Weight is a measure of the gravitational pull on matter. • Mass does not depend on gravity.

  13. Section2 Units of Measurement Chapter 2 SI Base Units Length • Length is a measure of distance. • The SI standard for length is the meter. • The kilometer, km, is used to express longer distances • The centimeter, cm, is used to express shorter distances

  14. Section2 Units of Measurement Chapter 2 E. Derived SI Units • Combinations of SI base units form derived units. • pressure is measured in kg/m•s2, or pascals

  15. Section2 Units of Measurement Chapter 2 Derived SI Units, continued Volume • Volumeis the amount of space occupied by an object. • The derived SI unit is cubic meters, m3 • The cubic centimeter, cm3, is often used • The liter, L, is a non-SI unit • 1 L = 1000 cm3 • 1 mL = 1 cm3

  16. Section2 Units of Measurement Chapter 2 Derived SI Units,continued Density • Densityis the ratio of mass to volume, or mass divided by volume. • The derived SI unit is kilograms per cubic meter, kg/m3 • g/cm3 or g/mL are also used • Density is a characteristic physical property of a substance.

  17. Chapter 2 Section2 Units of Measurement Notecard: Density Formula • Density: • D = • Volume: • V = • Mass: m V mD m = D x V

  18. Section2 Units of Measurement Chapter 2 Derived SI Units,continued Density • Density can be used as one property to help identify a substance

  19. Significant Figures Overview

  20. Multiplication and Division using SigFigs • Answers can have no more sig figs than least number of sig figs in the measurements used. • 12.59 x 3.45 = 43.4355 • BUT 3 sigfigs = 43.4 • 12.5 ÷ 3.45 = 3.649275362318841 • BUT 3 sigfigs = 3.65

  21. Section2 Units of Measurement Chapter 2 Derived SI Units,continued • Sample Problem A (p.37) • A sample of aluminum metal has a mass of • 8.4 g. The volume of the sample is 3.1 cm3. Calculate the density of aluminum.

  22. Section2 Units of Measurement Chapter 2 Derived SI Units,continued • Sample Problem A Solution • Given:mass (m) = 8.4 g • volume (V) = 3.1 cm3 • Unknown:density (D) • Solution:

  23. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set A (p.38) • 1. What is the density of a block of marble that occupies • 310.cm3 and has a mass of 853g?

  24. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set A (p.38) • 2. Diamond has a density of 3.26 g/cm3. What is the mass of a diamond that has a volume of 0.351cm3?

  25. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set A (p.38) • 3. What is the volume of a sample of liquid mercury that has a mass of 76.2g, given that the density of mercury is 13.6g/mL?

  26. Section2 Units of Measurement Chapter 2 Conversion Factors • A conversion factor is a ratio derived from the equality between two different units that can be used to convert from one unit to the other. • example:How quarters and dollars are related

  27. Section2 Units of Measurement Chapter 2 Conversion Factors, continued • Dimensional analysis is a mathematical technique that allows you to use units to solve problems involving measurements. • quantity sought = quantity given × conversion factor • example: the number of quarters in 12 dollars number of quarters = 12 dollars × conversion factor

  28. Section2 Units of Measurement Chapter 2 Using Conversion Factors

  29. Section2 Units of Measurement Chapter 2 Conversion Factors, continued Deriving Conversion Factors • You can derive conversion factors if you know the relationship between the unit you have and the unit you want. • example:conversion factors for meters and decimeters

  30. Section2 Units of Measurement Chapter 2 SI Conversions

  31. Section2 Units of Measurement Chapter 2 Conversion Factors, continued • Sample Problem B (p. 41-2) • Express a mass of 5.712 grams in milligrams and in kilograms.

  32. Section2 Units of Measurement Chapter 2 Conversion Factors, continued • Sample Problem B Solution • Express a mass of 5.712 grams in milligrams and in kilograms. • Given:5.712 g • Unknown:mass in mg and kg • Solution:mg • 1 g = 1000 mg • Possible conversion factors:

  33. Section2 Units of Measurement Chapter 2 Conversion Factors, continued • Sample Problem B Solution, continued • Express a mass of 5.712 grams in milligrams and in kilograms. • Given:5.712 g • Unknown:mass in mg and kg • Solution:kg • 1 000 g = 1 kg • Possible conversion factors:

  34. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set B (p.40) • 1. Express a length of 16.45 m in centimeters and in kilometers.

  35. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set B (p.40) • 2. Express a mass of 0.014 mg in grams.

  36. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems • Set B (additional) • 3. Would you be breaking the speed limit in a 40 mi/h zone if you were traveling at 60 km/h? Show work. • one kilometer = 0.62 miles

  37. Section2 Units of Measurement Chapter 2 2.2 Practice Problems (additional problem) 3. Would you be breaking the speed limit in a 40 mi/h zone if you were traveling at 60 km/h? • one kilometer = 0.62 miles • 60 km/h = 37 mi/h • You would not be speeding! • km/h and mi/h measure the same quantity using different units

  38. Chapter 2 Section2 Units of Measurement 2.2 Practice Problems (additional) • Set C (p. 58) • 16-23

  39. Section2 Units of Measurement Chapter 2 Objectives • Distinguish between a quantity, a unit, and a measurement standard. • Name and use SI units for length, mass, time, volume, and density. • Distinguish between mass and weight. • Perform density calculations. • Transform a statement of equality into a conversion factor.

  40. Chapter 2 Vocabulary • 6. quantity • 7. SI • 8. weight • 9. derived unit • 10. volume • 11. density • 12. conversion factor • 13. dimensional analysis

  41. End of Section 2 Show

More Related