Tuesday, January 21, 2014
How accurate should you be when you weigh or measure something? Let's use the weight of STEM Doodler Sydnie for an example:
Sydnie weighs 5.7 stones (A stone is 14
pounds)
Weight in pounds: 80 lbs
Weight in ounces: 1280 oz
Weight in kilograms: 176 kg
Weight in grams: 176,000 g
Weight in milligrams: 176,000,000 mg
If we weighed Sydnie in milligrams,
every time Sydnie breathed in or out her weight would change.
How small is a milligram? By
definition, one cubic centimeter is equal to one centigram of water.
So, one cubic millimeter is equal to one milligram of water.
How small is a millimeter? Let's say we
have a meter stick which measures 39.37 inches or a little bigger
than a yard. Converting this amount into millimeters would yield
1,000 millimeters, which is the smallest unit on the meter stick.
Milligrams work for some measurements, but not for them all. Take ground beef for example. You wouldn't want to buy ground beef in
stones nor would you want to use milligrams, so instead we would use pounds and ounces while the rest of the world uses kilograms and grams.
Also remember that there are smaller units than the
millimeter. These include micro, nano, pico, femto and atto. Each one
is ten times smaller than the previous. An atto meter is very small.
Also
There are larger units than the
kilometer. Each of these are ten times larger than the one previous
one before. These measurements include mega, giga, tera, peta, and
exa. An exameter is very big.
But
How about outer space? There we would use
light years or the speed of light (186,000 miles per second) during
one year or about 6.8 trillion miles.
If we wanted to measure Sydnie more
accurately, we could weigh her to the nearest microgram and we
would know how much her weight changed as she breathed in and out. In conclusion, there are many ways to use weight and measure, but not all of them are used for the same types of elements.
Measurements created and written by Jack Owens
