How long would the yarn supn from a single sheep's wool be?
November 4, 2011 2:10 PM Subscribe
This is a Fermi Question, I only need an approximate answer: How long would the yarn spun from a single sheep's wool be? Is 2 miles reasonable? What's a good lower bound?
posted by ch3cooh to science & nature (10 answers total)
My first instinct is that two miles is way too long, but here's how I got that initial guess:
I found a standard type of wool yarn that is priced at $14/ 200g or 220 yards, so, the yarn must be about 1g/yard
I also looked up the average annual yield of wool from a sheep: "In 2007, the average sheep in the U.S. produced 7.3 lbs. of grease wool." -- reliable website
There are 1760 yards in a mile, and 453 grams in a pound.
Thus, 7lbs*450g/lb= 3150 grams of wool = 3150 yards of wool = approximately two miles of wool yarn...
but this number just doesn't seem right! Where am I going wrong and what's a better estimate for the approximate length of wool yarn that would be produced by a sheep in a year.
Any help appreciated! Thanks!