Metric Mania: Length
by Josiah Lemay
The Basis of the Meter
In 1790, it was originally declared a meter was one ten-millionth of the distance between the north pole and the equator (measured along a meridian in France). However, as of 1980, the length of the meter is identified as 1,650,763.73 wavelengths of orange-red light, specifically produced by the burning of krypton in a vacuum. To the right is one of the 30 copies of the physical meter.
Cheez-Its Box
The best prefix measurement for this box would be centimeters. The box is not so large that meters or decimeters would be required to measure it's dimensions, but not so small that millimeters would be more preferable or accurate.
- Height = 32.5 cm, 325 mm, 0.000325 km
- Length = 24.4 cm, 244 mm, 0.000244 km
- Width = 12.4 cm, 124 mm, 0.000124 km
AA Battery
Millimeters would be best used for the battery as it is too small to fit more precisely into a measurement of centimeters, decimeters, or meters.
- Length = 50.3 mm, 0.503 dm, 0.0503 m
- Diameter = 13.7 mm, 0.137 dm, 0.0137 m
Refrigerator
In the case of the refrigerator, the meter is the most appropriate prefixed measurement because it yields numbers that are frankly more easy to look at it and immediately identify, as the dimensions of the fridge in meters are able to be rounded to the nearest ones or tens place.
- Height = 1.72 m, 17.27 dm, 172.7 cm
- Width = 0.94 m, 9.39 dm, 93.9 cm
- Length = 0.67 m, 6.67 dm, 66.7 cm
Dimensional Analysis in Real Life?
Dimensional analysis can be seen in everyday life in many different ways, including, but not limited to
- building a house, car, or anything. You need to know what parts fit where, which means knowing their exact size and dimensions could be extremely useful and possibly less tedious than just guessing and placing.
- flying a plane. When in this situation, you need to know what your surroundings are. Just knowing your distance from the ground could be helpful in making a quick, easy, and safe landing.
- fixing machinery, furniture, or supplies. In order to fix something in the most optimal way possible, you have to know an awful lot about what you're fixing (its dimensions included). Knowing the length, height, and width of an object you may be attempting to reconstruct is also required when you're trying to find a replacement part to a piece of work that may be made up of multiple segments.
Class Activity
- How many centimeters long is your desk if it is 6 feet in length? - Hint: 30.48 cm = 1 inch
- Find the volume of a CD case that is 30.3 centimeters in length, 4.32 decimeters in height, and 245.7 millimeters in width.
- Dave jumps a height of 1.3 meters. You jump a height of 105 centimeters. What is the difference in your jump heights in millimeters?