conversion

Metric System
1000 m = 1 km
1 inch = 2.54 cm
1 m = 100 cm
1 gallon = 3.785 L
1 m = 1000 mm
101.325 Pa = 1 atm
1 L = 1000 mL
1 foot = 12 inches
1000 g = 1 kg
1 mile = 5280 ft

Metric System
60 s = 1 hr
24 hrs = 1 day
365 days = 1 year
100 yr = 1 century
1 atm = 760 mmHg



Dimensional analysis:
The technique of converting between units is called dimensional analysis.


Conversion factors: Conversion factors are the ratios of equivalent measurements. It can also be used when converting from English to Metric and vice-versa. In a conversion factor, the numerators on both sides of the equation are equal.
Ex. = = 1
or = = 1
How do you know which unit of a conversion factor must be in the denominator? The unwanted units are placed at the bottom so that they will be cancelled out; the desired unit is on top so that it would be retained.
Ex. Convert 5.6 dm (decimeter) to meters.
The problem is: ? m = 5. 6 dm


By definition, 10 dm = 1 m
Therefore we write,
(5.6 dm) (1 m) /(10 dm) = 0.56 m