Chapter 8
Factor – Label Method
Part 1
You have just used a conversion factor.
Conversion Factor
A relationship between two units
expressed in fractional form
Conversion Factors• A conversion factor is a ratio:
12 inches or 1 foot
1 foot 12 inches
Factor Label Method
Method of converting from one unit to another using
conversion factors
24 in. = ___ ft.
We can solve this problem using factor label method.
Prefix Symbol Value Power Use
Giga G 1,000,000,000 109 Gigabyte
Mega M 1,000,000 106 Megawatt
kilokilo kk 1,0001,000 101033 kilometerkilometer
deci d 0.1 10-1 decigram
centicenti cc 0.010.01 1010-2-2 centimetercentimeter
millimilli mm 0.0010.001 1010-3-3 millilitermilliliter
micro 0.000001 10-6 microsecond
nano n 0.000000001 10-9 nanometer
Prefixes in the Metric SystemPrefixes in the Metric System
An Example of a Metric Conversion Factor
• 1000 m = 1 km
km1
1000m
1000m
km1
This can be written as the factors ...
An Example Problem …
• Convert 10.83 cm to meters using the Factor Label Method.
Convert 10.83 cm to meters
10.83cm
Convert 10.83 cm to meters
10.83cm
cm
Convert 10.83 cm to meters
10.83cm
cm
m
Convert 10.83 cm to meters
10.83cm
cm
m0.01
Convert 10.83 cm to meters
10.83cm
cm
m0.01= 0.1083 m
Convert 152dg to mg
152dg
Convert 152dg to mg
152dg
dg
Convert 152dg to mg
152dg
dg
g
Convert 152dg to mg
152dg
dg
0.1g
Convert 152dg to mg
152dg
dg
0.1g
Convert 152dg to mg
152dg
dg
0.1g
g
Convert 152dg to mg
152dg
dg
0.1g
g
mg
Convert 152dg to mg
152dg
dg
0.1g
g
mg
0.001
Convert 152dg to mg
152dg
dg
0.1g
g
mg
0.001= 15,200mg
Convert 6896s to weeks
6896s
Convert 6896s to weeks
6896s60smin
Convert 6896s to weeks
6896s60smin
60minhr
Convert 6896s to weeks
6896s60smin
60minhr
24hrday
Convert 6896s to weeks
6896s60smin
60minhr
24hrday
7 daysweek
Convert 6896s to weeks
6896s60smin
60minhr
24hrday
7 daysweek
= 0.01140 weeks
Convert 150.0 mg/hr to cg/year
Convert 150.0 mg/hr to cg/year
150.0mg
hr
Convert 150.0 mg/hr to cg/year
150.0mg
hr
0.001g
mg
Convert 150.0 mg/hr to cg/year
150.0mg
hr
0.001g
mg 0.01g
cg
Convert 150.0 mg/hr to cg/year
150.0mg
hr
0.001g
mg 0.01g
cg 24 hr
day
Convert 150.0 mg/hr to cg/year
150.0mg
hr
0.001g
mg 0.01g
cg 24 hr
day
365 days
year= 131,400 cg/year
How many minutes does it take light to reach us from the sun which is
93,000,000 miles distant.
• The following information will be useful:– speed of light = 3.0 x 108 m/s – 1km = 0.6214 mi