Concepts to Investigate: Fundamental units, derived units, factor labels, dimensions. Materials: none.
Principles and Procedures: When crossing the border to Canada, American motorists are often surprised to see speed limits of
"90" or "100". If they don't realize that Canadians measure speed in kilometers/hr while Americans measure in miles/hr (1.00
mile/hr = 1.61 kilometers/hr; 60 miles/hr = 97 km/hr) they may soon be in for trouble with the law. If, for example, an
American motorist accelerates until her speedometer (measured in miles/hr) reaches "100", she will be traveling 38 miles/hr over
the posted speed limit of 100 km/hr since a speed of 100 km/hr is equal to only 62 miles/hr. As this example illustrates,
measurements without units are meaningless and may lead to serious misunderstandings. Everything that can be measured must
be expressed with appropriate units.
Units in everyday life: We use units everyday, often without even realizing it. In the statements that follow you will
find a wide variety of interesting facts, but each is missing a crucial piece of information -- the dimensions (units)! All the
statements are meaningless until you supply the appropriate units. On the basis of your experiences, try to match the appropriate
units from the list provided.
carats
cm
degrees Celsius
degrees Fahrenheit
feet
grams/ml
inches
kcal (Cal)
kilograms
kilometers
kilowatt-hours
liters
megabars
miles
miles per hour
milligrams
pounds
stories
tons
yards
(a) America's tallest building (Sears Tower in Chicago) is 110 ___ high.
(b) The Empire State Building in New York is 1250 ___ high.
(c) The Nile is the world's longest river. It is 4180 ___ long.
(d) The Amazon River in South America is ___ 6296 long.
(e) The coldest temperature ever recorded was -128.6 in Vostok, Antarctica in 1983.
(f) The highest recorded temperature in the United States was in Death Valley, California when the mercury reached 57
!
(g) The world record rainfall occurred in Cherrapunji, India where 1042 ___ of rain fell in one year.
(h) The largest recorded hailstone to ever fall landed in Coffeyville, Kansas in 1979. It had a diameter of 44.5 !
(i) The longest punt in NFL history was by Steve O'Neal of the new York Jets. He kicked the football 98.
(j) The largest seed in the world is that of the coc-de-mer coconut tree, which may weigh as much as 40 !
(k) The world's largest meteorite is located in Southwest Africa. It weighs 650 .
(l) The most popular soft drink in the World is currently Coca Cola". More than 210 million were consumed
each day in 1990.
(m) The largest diamond in the world was mined from South Africa in 1905 and weighs 3,106 .
(n) Earth is the densest of the nine planets, with an average density of 5.515 .
(o) The world's fastest aircraft is the Lockheed SR-71 Blackbird, clocking a record speed of 2,193.67.
(p) The largest gold nugget ever found had a mass of 100 !
(q) One large chicken egg contains an average of 274 cholesterol.
(r) A 16-year old male requires an average of 2800 of energy per day while a an average 16-year old female requires
only 2100.
(s) The United States produces and consumes more electric energy than any other nation. Each year the United States
produces over 2500 billion .
(t) The largest pressure ever developed in a laboratory was 1.70 , used to solidify hydrogen in 1978