Converting to Square UnitsDate: 01/07/2002 at 09:11:56 From: Joey Subject: Converting to kilometers How do I convert the number 47,224 sq miles to kilometers? Date: 01/07/2002 at 10:08:21 From: Doctor Ian Subject: Re: Converting to kilometers Hi Joey, Strictly speaking, you can't. Square miles are a measure of area, and kilometers are a measure of length. Do you mean, how can you convert square miles to square kilometers? Let me show you how to do it with different units, and you can apply the same reasoning to your own problem. Suppose I have something that is 4 square inches in area: 1 in 1 in +---------+--------+ | | | | | | 1 in | | | +---------+--------+ | | | | | | 1 in | | | +---------+--------+ Now, I know that there are 2.54 centimeters in an inch. So I can label my picture this way: 2.54 cm 2.54 cm +---------+--------+ | | | | | | 2.54 cm | | | +---------+--------+ | | | | | | 2.54 cm | | | +---------+--------+ So the area is cm is (2 * 2.54) * (2 * 2.54) If we look a little more closely, we can see what is going on: 4 in^2 = (2 in) * (2 in) 2.54 cm 2.54 cm = (2 in * -------) * (2 in * -------) 1 in 1 in 2.54 cm = (2 in) * (2 in) * (--------)^2 1 in 2.54 cm = 4 in^2 * (--------)^2 1 in So whereas for length, I would multiply by a conversion factor, e.g., 35 ziglofs 21 blinches * ----------- = 21 * (35/17) ziglofs 17 blinches for area I have to multiply by the square of the conversion factor, e.g., 35 ziglofs 21 blinches^2 * (-----------)^2 = 21 * (35/17)^2 ziglofs^2 17 blinches Does that make sense? (Can you guess what you have to do for volume?) There are 1.609 kilometers in a mile. Can you take it from here? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/