Wikipedia:Reference desk/Archives/Science/2016 June 30

= June 30 =

Threaded joints
What's the formula for calculating the maximum tensile stress a threaded joint can withstand without damage (stripping of threads, etc.)? 2601:646:8E01:7E0B:F843:A86F:E19:3477 (talk) 00:13, 30 June 2016 (UTC)
 * A Structural Engineer in my office (who spends all day calculating whether steel towers will fail under various loads or not) has just dictated the following to me:
 * "Calculate the cross-sectional area of the screw at the root of the thread and multiply this by the allowable tensile stress of the material of the bolt. E.g. an M12 screw has XSA of 84.3mm2 and for a grade 4.6 bolt the UTS will be 600 N/mm2, giving 50580 N tensile strength, but material safety factors will reduce this value down."
 * As I'm a pre-accountant, I don't claim to understand any or that, and no liability is accepted. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 13:46, 30 June 2016 (UTC)
 * These links may help:, , . AllBestFaith (talk) 14:13, 30 June 2016 (UTC)
 * Thank you! And am I correct that these formulas apply to pipes just as well as to solid bolts (with correction for the hollow part), as I think they do? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 20:52, 30 June 2016 (UTC)

Food consumption
Why is it that I can eat a large pizza in one sitting before I feel full, but if I try to eat a candy bar I can hardly finish it and vow to never eat again? (Why can I eat 2 pounds of one food but can hardly manage a couple ounces of another food?) 199.19.248.122 (talk) 02:13, 30 June 2016 (UTC)
 * Hunger (motivational state) talks a bit about it. Osmotic pressure can affect a high sugar food. Graeme Bartlett (talk) 02:42, 30 June 2016 (UTC)
 * The OP's statement is counterintuitive and contrary to common experience. Is there any reliable source which says it is easier to eat 2 pounds of pizza than to eat 2 ounces of candy bar? Edison (talk) 02:49, 1 July 2016 (UTC)
 * It could be that the OP has kind of an aversion to highly-sweet stuff. I like things that are moderately sweet, but some things are so sweet they're almost nauseating. An example that comes to mind is a caramel milkshake. Very tasty at first, but it can get to be too much. ←Baseball Bugs What's up, Doc? carrots→ 03:48, 1 July 2016 (UTC)


 * It might have something to do with leptin and/or ghrelin, but someone with a background in biochemistry would need to explain. See also: Hunger (motivational state) --2606:A000:4C0C:E200:1904:9CA2:35F0:1D79 (talk) 06:26, 1 July 2016 (UTC)