OMG - what is the inside diameter of inch and a quarter PVC pipe?

[Kali]

81 replies! :rofl:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=439x1595686

HINT: not 1/25 inches - and that isn't the outside diameter either!

[Ptah]

1. 400 gallons.

Final answer.

[pokerfan]

2. That's what I got, more or less

And no one took me up on my puzzler: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=439&topic_id=1595686&mesg_id=1597505

:(

[Ptah]

3. That one has me still thinking.

:headscratch:

[pokerfan]

4. Try drawing a graph of what's going on

Distance on the vertical axis and time on the horizontal. We don't know either of the speeds so just guess. Turns out it doesn't matter as long as they remain constant and walking is much slower than driving.

I couldn't solve it without being shown how.

[ashling]

12. Is it farther to New York

or by bus?

[pokerfan]

13. Did you walk to school today

or bring your lunch? :)

[Kali]

6. I'm too exhausted for that!

:rofl:

[Kali]

5. and you, my friend, had it right and first

probably should have just PM'd you!:rofl:

[kentauros]

7. Answer: Pocket Ref!

http://www.amazon.com/Pocket-Ref-Thomas-J-Glover/dp/1885071000

That's the fourth edition, while I'm still looking up stuff in my 1st edition :P

Such as your answer to the OD found on page 321 for Schedule-40 PVC pipe, Nominal size 1-1/4: Actual OD 1.66", with a wall-thickness of 0.140" (0.191" for S-80). Actual ID works out to 1.38"

I'm not bothering with the rest of the answer per that other thread. Just giving you the info from the handiest reference book evah! :D

[kentauros]

8. Okay, I went ahead and did it.

And I get ~410 gallons.

1 Gal = 231 cu.in.
1 mile = 63360 inches
ID = 1.38"
r = 0.69"
h = 63360"


pi * r squared * h =
3.14~ x (0.69")2 x 63360 =
3.14~ x 0.4761 x 63360 = 94768.32894 cu.in. / mile

94768.32894 cu.in. / 231 cu.in. = 410.2525063 gal. (410 gal., 1 qt., 2 tsp)

:P

[pokerfan]

11. I concur

though I used from 1.36" for the I.D. per an online datasheet.

[kentauros]

15. Yeah, that's the kind of sliderule a drafter would design,

just to piss off the people in the shop, see if they'd really build it that big and never think about the dimension numbers :P

[pokerfan]

17. I just missed having to learn slide rule in high school

but I was sort of the science teacher's pet and had access to the store room where I discovered the old wall-sized instructional slide rule. So I dragged it out and made him teach me how to use it. I was a real dork in high school.

[kentauros]

19. I never learned how to use one.

It was hard enough learning how to use a micrometer.

Although Wikipedia has a really helpful animation:

[pokerfan]

21. Cool, I've used those on occasion

Here's a virtual slide rule:

http://www.antiquark.com/sliderule/sim/virtual-slide-rule.html

If you remember your logarithms you might recall that adding two logarithms together gives you the logarithm of the product. So on the slide rule you measure out one number on the D scale and then add the other number on the C scale. For example, this is the position for 2 * 3 = 6:



I keep a cheapo six inch Pickett in the glove box for figuring gas mileage. Never needs batteries and it's a great conversation starter.

[hunter]

20. When I was in high school some math classes had giant slide rules like that.

Lessons and homework for which we could use slide rules were a lot more fun than lessons that required tables. Log and trig tables were simply dreary and depressing. I like things that move.

By the time I started college scientific calculators were less expensive than good slide rules. The transition from slide rules and tables to calculators was rapid.

[pokerfan]

22. I remember having to interpolate & extrapolate log tables

Ugh! Somehow they saw fit to teach us that useless skill in 1974 but not the slide rule. Why would anyone be fooling with log tables in 1974?

I've owned many, many hp calculators over the years but this one is my favorite:


This one was my first:


You never forget your first. :) I still have it and I've even modified to battery pack to accept AA batteries.

[pokerfan]

9. Some of the answers

for # of gallons in a mile of your pipe:

5.99
228
333.7
398.447299
400
400.8
1242.11

Good thing this bunch isn't trying to do something important like flying to the Moon.

:rofl:

[Kali]

14. hey! you left out my 300 guess

:rofl:

[Ptah]

23. Adding in Kali's 300, the average of those guesses is:

413.6

[dimbear]

10. PVC pipe is crudely manufactured. It varies.

Offhand, safe to say less than a furlong.

[kentauros]

16. Yeah, you'd do better to just dig a ditch,

line it with plastic and make an irrigation channel before relying on huge variances of plastic pipe IDs! :P

[struggle4progress]

18. Two and a half feet

[dimbear]

24. Imperial gallons or Spanish gallons like the Spanish Armada? n/t

[HopeHoops]

25. About the same as the air speed velocity of an unlaidened swallow (European).