This document discusses measurement standards and the International System of Units (SI). It provides definitions and examples of common units used to measure length, mass, temperature, time, area, volume, density, and weight. Key points covered include: 1) Early measurement standards were based on body parts but were inconsistent; the meter and kilogram were established as consistent base SI units. 2) All measurements require both a number and a defined unit, such as "5 meters". 3) Common prefixes are used to modify base units to measure very large or small quantities. 4) Different instruments are used to measure different physical properties, such as thermometers for temperature and balances for mass.

1. Unit 1 Using SI Units

2. Measurement Standard An exact quantity that people agree to use for comparison. * helps you get the same answer as other people

3. What was used as the earliest measurement standards? Body Parts * The question then, is WHO’S body parts? The KING’S or QUEEN’S

4. Is your hand or a body part a good standard of measurement? * no * people’s hands are not the same size * get different answers

5. In order for any measurement to MAKE SENSE; two things must be included. 1.) a number 2.) a unit

6. Every type of measurement has a base or central unit. * meter (distance or length) * liter (volume) * gram (mass) * second (time)

7. Adding a prefix to a base (central) unit, you can create a whole new unit to measure any object.

8. Prefixes Used When Measuring: Large Objects kilo = 103 hecto = 102 deka = 101 Small Objects deci = 10-1 centi = 10-2 milli = 10-3

9. Measurements that can be made Length Mass Temperature Time Area Volume Density Weight

10. Length The distance between two points. Base (central) units of length * (US) FOOT [ft] * (SI) METER [m]

11. Length Length of an object or the distance between two points is measured using a METERSTICK.

12. Mass “A body of coherent matter.” * a collection of stuff joined to form an object Base (central) units of mass * (US) SLUG [slug] * (SI) KILOGRAM [kg] sometimes gram [g]

13. Mass Mass is measured using a BALANCE.

14. Temperature Measurement of how hot or cold something is.

15. Temperature Base (central) units of temperature * (US) FAHRENHEIT [oF] * (SI) CELCIUS [oC] > (SI) KELVIN [K] * this is an absolute scale

16. Temperature Temperature is measured using a THERMOMETER.

17. Absolute Zero The coldest possible temperature. * temperature where ALL motion stops * 0 Kelvin * found by the formula: K = oC + 273.16

18. Time Interval between two events. Base (central) units of time * (US) SECOND [s] * (SI) SECOND [s]

19. Time Time can be measured using a CLOCK or a CALENDAR.

20. Derived Units Obtained by combining multiple units of measurement.

21. Area The amount of surface included in a set of boundaries. Found by the formula: * Area = lengthx width

22. Area What is the difference between length and width? DIRECTION

23. Area Base units of area * (US) FEET SQUARED [ft2] * (SI) METERS SQUARED[m2]

24. Volume The amount of space an object occupies. Easy with liquids & gases, harder with solids * for a solid you may need the formula: volume = l x w x h

25. Volume For a liquid or a gas all you need is a devise that is designed to measure volume. * a beaker, a flask or a graduated cylinder

26. Volume Base (central) units of volume * (US) GALLON [gal] * (SI) LITER [L] sometimes centimeters cubed [cm3]

27. Volume 1 milliliter equals 1 centimeter cubed. * 1 mL = 1 cm3

28. Density The measurement of how thick, compact and solid an object is. Relationship between the mass & volume of an object

29. Density Found by the formula: * Density = mass ÷ volume Expressed in g/Lorg/cm3 * a mass unit / a volume unit

30. Weight Measurement of the force of gravity pulling on the mass of an object. Changes as gravity changes. Base units of weight * (US) POUND [lb] * (SI) NEWTON [N]

31. Weight Weight is measured using a SPRING SCALE.

32. MASS and WEIGHT are NOT the same thing!

33. Physical Properties Characteristics of a substance that can be used to identify it. Color Shape Texture State of matter Size All measurements (changing a physical property does NOT change the substance)

34. The End