Units of Measurement

1
Units of Measurement

• Objectives
• Process Skill D Measuring - Using appropriate
  metric units for measuring length, volume, and
  mass.

2
SI Base Units
Quantity Base Unit Unit Abbreviation
1. Time
2. Mass
3. Temperature
4. Length
5. Amount of a substance
3
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G
mega M
kilo k
deci d
centi c
milli m
micro µ
nano n
pico p
4
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M
kilo k
deci d
centi c
milli m
micro µ
nano n
pico p
5
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 ?
kilo k
deci d
centi c
milli m
micro µ
nano n
pico p
6
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 ?
deci d
centi c
milli m
micro µ
nano n
pico p
7
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 ?
centi c
milli m
micro µ
nano n
pico p
8
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) ?
milli m
micro µ
nano n
pico p
9
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) 10-2
milli m 1/1000 (0.001) ?
micro µ
nano n
pico p
10
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) 10-2
milli m 1/1000 (0.001) 10-3
micro µ 1/1,000,000 (0.000001) ?
nano n
pico p
11
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) 10-2
milli m 1/1000 (0.001) 10-3
micro µ 1/1,000,000 (0.000001) 10-6
nano n 1/1,000,000,000 (0.000000001) ?
pico p
12
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) 10-2
milli m 1/1000 (0.001) 10-3
micro µ 1/1,000,000 (0.000001) 10-6
nano n 1/1,000,000,000 (0.000000001) 10-9
pico p 1/1,000,000,000,000 ?
13
SI Prefixes
Prefix Abbreviation Equals Scientific Notation
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1000 103
deci d 1/10 or 0.1 10-1
centi c 1/100 (0.01) 10-2
milli m 1/1000 (0.001) 10-3
micro µ 1/1,000,000 (0.000001) 10-6
nano n 1/1,000,000,000 (0.000000001) 10-9
pico p 1/1,000,000,000,000 10-12
14
Base Units

• Base units are defined units based on an object
  or event in the physical world
• Meter distance light travels through a vacuum
  in 1/299,792,458 of a second (or 2.99792458 x
  10-8 seconds)
• Kilogram mass of a platinum-iridium cylinder
  that is stored at constant temperature and
  humidity

15
Derived Units

• Units made up of a combination of base units
• Speed meters/second
• Volume
• cubic meter (m3) or cubic centimeter (cm3)
• Liter (or cubic decimeter dm3)
• How is this a combination of base units?
• Density mass/volume (g/mL or g/cm3 )

16
Using Density and Volume to Find Mass

• You have a cylinder with a volume of 150 mL and a
  mass of 75 g. What is its density?
• Known values
• V 150 mL
• m 75 g
• Formula
• Density mass/volume 75 g/150 mL
• Density 0.5 g/mL

17
Problem-Solving

• If dm/V, rearrange the formula to solve for m. m
  ?
• If d m/V, rearrange the foemula to solve for V.
  V ?
• Example Problem (p.29)
• Assignment Practice Problems (p.29)