Talk:Conversion of units/Archive 2011

Removal of variable suggestions
I have removed the variable suggestions for several reasons.
 * No reference was provided to show these were the correct variables to use.
 * No explaination was provided to show these were variable suggestions.
 * The variable used for a certain quantity can vary from one field to another.
 * Some of the variables for scalar quantities were in boldface, which often is reserved for vectors.
 * Most of the variables were in upright type, but variables are usually put in italic type. --Gerry Ashton (talk) 20:17, 22 January 2008 (UTC)

PLEASE CAN SOMEONE DO A USEFUL CONVERSION TABLE FOR THE LAY PERSON! I'm sorry that this comment may not belong here, but I didn't see where else to put is. Please let me know where would be better. I've been doing editing for Wikipedia for a number of years on different topics - certainly not mathematics.

But we REALLY need a USEFUL conversion table. I was simply trying to convert 120 ml to oz., and it is REALLY difficult with the current conversion table. (Actually, I'm not sure if it is even possible with the current table, which is pretty sad.)

Could someone please help?

Thanks very much.

Kris Wood sfbaybreezes@yahoo.com — Preceding unsigned comment added by Kristinamwood (talk • contribs) 21:49, 2 April 2011 (UTC)

Length conversions not adding up (1 mile = 1.609344 kilometers?)...
........It seems to me that the conversion to and from Standard and Metric should be fairly easy for things such as length. For example, a basic Standard unit is the inch, and a basic Metric unit is the centimeter. To convert between them, 1 inch equals 2.54 centimeters, and one centimeter equals .3937 (plus a tiny bit more) inches, and there doesn't seem to be any disagreement on this.

........There are 12 inches in a foot, and 5280 feet in a mile. So, one mile is 63,360 inches. One kilometer is 100,000 centimeters. 100,000 divided by 63,360 is 1.57 82, so one mile should equal 1.57 82 kilometers, and one kilometer should equal .6336 miles.

........So, my question is, where exactly do we get the figure of 1.609344 kilometers per mile? That isn't even close. The impetus for this post is that I was a short while ago attempting to calculate the circumference of VY Canis Majoris, which is ordinarily measured either in AUs, or in thousands of solar radii, and I've learned from experience that I unfortunately cannot trust the figures given on Wikipedia to be accurate representations of values given in miles. When you're dealing with converting thousands of solar radii to miles, the difference between 1.57 82 and 1.609344 can add up very quickly. So, I'm just wondering, where is it that we get the latter value from, and why isn't it simply a matter of the multiplication and division of inches and centimeters to ascertain the conversion values for other Standard and Metric units? Any input or insight anyone can offer would be much appreciated.  -=( A l e x i s (talk) 23:17, 1 August 2011 (UTC) )=- 
 * A mile is 63,360 in × 2.54 cm/in ÷ 100 cm/m ÷ 1000 m/km = 1.609344 km. JeffConrad (talk) 23:31, 1 August 2011 (UTC)


 * To follow up and expand on Jeff's answer, this is what you've done (hint: look at the units):
 * 100,000 cm/km ÷ 63,360 in/mi = 1.57$\overline{82}$ cm/km · mi/in
 * We can rearrange the units to display as
 * 1.57$\overline{82}$ cm/in · mi/km
 * To get to a miles/kilometers equivalence, we need to get rid of the cm/in, so:
 * 1.57$\overline{82}$ cm/in · mi/km × 1 in/2.54 cm = 0.62137 mi/km (roughly)
 * When we take a reciprocal of that, we get 1.609344 km/mi
 * (In short, you left out the inches-to-centimeters conversion.) BW95 (talk) 03:14, 2 August 2011 (UTC)
 * Um, no, I don’t think so: “63,360 in × 2.54 cm/in”. JeffConrad (talk) 03:48, 2 August 2011 (UTC)
 * I was addressing Alexis's original question. He or she had left out the cm/in conversion and ended up with the wrong number. BW95 (talk) 04:12, 2 August 2011 (UTC)
 * So I now see. JeffConrad (talk) 05:04, 2 August 2011 (UTC)

Conversion of RPM
can somebody please tell me the SI unit for R.P.M — Preceding unsigned comment added by 82.128.13.136 (talk) 09:38, 12 October 2011 (UTC)


 * RPM would be converted to hertz. Each revolution would be considered a cycle, so just divide the RPM by 60 to find hertz. If this is being done for an electric generator, keep in mind that one revolution of the rotor may produce several cycles of electric energy. Jc3s5h (talk) 14:27, 12 October 2011 (UTC)