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. Measurement of how hot or cold something is.
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

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 = length x 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/L or g/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. (changing a physical property does NOT change the substance)
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