Pete & sheri wrote:
I found this in a 1908 Audel's Millwright's Manual.

If you square the diameter of a circle and multiply by .7854, you get
the area of the circle. Also,4 X 0.7854 = Pi. With a little
thought, you can get along without pi, if you want to.

Okay, "So What?" you say.

Well, note that .7854 means that a circle that just fits into its
enscribed square contains 78.54% of the area of that square. And
that's about 80%. So, an easy way to ESTIMATE the area of a circle in
your head is to simply think "8 tenths of the area of the enscribed
square = the area".

Example: A guy offers you a piece of steel just for coming and getting
it off the place RIGHT NOW!
You need to know the approximate weight of a 5" diameter bar of steel
that is 5 feet long, so you can decide whether you will be able to lift
it into your car trunk by yourself.

So, 5 X 5 = 25. 80% of 25 (in your head) is 20. That's area of the
circle. 20 X 60 (5 feet in inches) is 1200. There's the volume of
the bar! That's all there is to it!

Now for the weight:

A cubic inch of steel weighs 0.283 pounds think 2 Ate 3 (cannibalism
of numbers???). 0.283 is about .3

So the bar weighs 1200 X .3 = (in your head) about 360 pounds.
Sorry, Maybe you can lift it, but I'd have to pass on this one!!!

Well, maybe I could------


Pete Stanaitis

Nonsense I don't believe this for one second . Let me see if I have it
right . 5 inch hunk of steel 5 feet long and anyone that frequents this
newsgroup would pass on it ? Ha ha , yea more likely they would be
tripping over each other to get there first . If anything we would see
50 posts on how this Rube Goldberg would lift it easier/safer then that
Rube Goldberg . Followed by 100 posts on whether Bush or Kerry in office
would affect how many jobs would be saved from going to China because
you kept this hunk of steel from being shipped to them as scrap . That
and anyone that tried to get between my and that hunk of steel better be
well armed . Opps there goes another 100 posts to determine in gun
packing metal scrongers threaten the world as we know it , :-)
Ken Cutt