Going MetricMetric Measurement Introduction
History of Measurements
In ancient times, as trade developed between cities and nations, units of measure were developed to measure the size of transactions and purchases.
History continued
During the Renaissance, as scientist began to develop ideas of physics and chemistry, they needed standard units of measure to communicate their ideas and theories effectively.
Beginnings of metric system
In March 1791, in Sevres, France, the French Academy of Science proposed a standardized system that would be easy to use.
This system is now called the SI system
French Le Systéme International d’Unités
LengthThey based their units of length on a fractional system of the distance between the equator and the North Pole.
The system’s basic unit of length measure was called the meter
Meter in Greek (metron) means measure
Today, length of a meter is defined as the distance light travels in a small fraction of a second
Origins of Common Metric Measurements
5 city blocks = 1 kilometer
Height of a 1st grader
1 meter
Width of your pinky
finger1 centimeter
Width of pencil lead
1 millimeter
Mass
1 kilogram is defined by a specific lump of platinum that is kept in Paris in controlled conditions to keep it from any chemical changes
You may wonder why the based unit for mass is the kilogram and not the gram
A gram is quite a small unit of mass
Volume
The liter is the base unit for volume
One milliliter (mL) is the volume of one gram (g) of water or one cubic centimeter of water
TemperatureThe base unit for the measure of temperature is one degree celsius (or centigrade if you’re old enough to remember this)
0° celsius = freezing (water)
100° celsius = boiling (water)
37° celsius = normal human body temperature
Modern DayMost of the world uses the metric system in daily life
You might be surprised to note that the US sanctioned the use of the metric system in 1884, but people have clung on to the use of the English or Imperial system
Since 1992, US government agencies have been required to use the metric system in business transactions
Meter (m)
Liter (L)
Kilogram (kg)
Metric Abbreviations - Base Units
Units of the metric system
Measurement Type
Base unit Unit Symbol
Mass kilogram kg
Volume liter l
Length/distance meter m
Temperature degree celsius ˚c
Metric Step Ladder
How to use Metric Step Ladder
1st - determine your starting point
2nd - count the “jumps” to your ending point
3rd - move the decimal point the same number of jumps
Metric Units - Length/Distance
1 Kilometer (km) = 1000 meters 3 jumps
1 Meter = 100 Centimeters (cm) 2 jumps
1 Meter = 1000 Millimeters (mm) 3 jumps
Measuring MassMass refers to the amount of matter in an object
1 kilogram = 1000 grams 3 jumps
1 gram = 1000 milligrams 3 jumps
We will be using a triple-beam-balance to measure mass
Interactive triple-beam-balance tutorial: http://www.ohaus.com/input/tutorials/tbb/tbbentry.swf
Measuring Volume
Volume is defined as the amount of space an object takes up
1 liter = 100 centimeters 2 jumps
1 mL (of water) = 1g = 1 cm3
measured: l ⨯ w ⨯ h
Measuring VolumeWe will be using graduated cylinders to find the volume of liquids
Measure at the bottom of the meniscus
Any ideas why?
To measure the volume of regular objects use: l ⨯ w ⨯ h