Wikipedia:Reference desk/Archives/Science/2016 June 9

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June 9

Is there a relation between capillary action and capillary blood vessels?

Kindly I would like to get sources for the answer. 93.126.88.30 (talk) 16:21, 9 June 2016 (UTC)

Read capillary and capillary action. The word "capillary" itself refers to hair, i.e. a fine strand of something. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:25, 9 June 2016 (UTC)

There is not a direct relationship because the blood does not depend on capillary action to make it flow. The blood flow is caused by vascular pressure from the heart and is regulated in the capillary by the Bayliss effect. AllBestFaith (talk) 23:38, 9 June 2016 (UTC)

Corporate culture in emergency services

In general, do emergency services personnel and frontline healthcare staff feel like corporate slaves? Are there any studies on this? 2A02:C7D:B965:D700:E0F6:67A9:FE9A:3BD (talk) 16:39, 9 June 2016 (UTC)

Clarify what you mean by "slaves". No one is being forced to work there. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:33, 9 June 2016 (UTC)

Are you unfamiliar with the term "wage slavery"? OP is using the term in a related, metaphorical manner. Also, the phrase "feel like" is not usually used as a synonym for "is a literal example of". SemanticMantis (talk) 19:34, 9 June 2016 (UTC)

Here [1] [2] [3] [4] are a selection of studies regarding some mix of mental health, job satisfaction and stress of emergency services personnel. The last one, on ambulance personnel, finds that

“ Approximately a third of the sample reported high levels of general psychopathology, burnout and posttraumatic symptoms. Burnout was associated with less job satisfaction, longer time in service, less recovery time between incidents, and more frequent exposure to incidents. ”

Hope that helps, SemanticMantis (talk) 19:34, 9 June 2016 (UTC)

Measuring strike on ball. with simple devices

If I connect a pressure gauge to a football ball and kick it, measuring the added pressure (gauge goes up to 100 psi) how can I convert this to force? — Preceding unsigned comment added by 212.163.6.23 (talk) 18:52, 9 June 2016 (UTC)

Alternatively: could I attach the ball with a cord to a post kick it and see how many times it spins around the post? It would be like a Tetherball, but at floor level. — Preceding unsigned comment added by 212.163.6.23 (talk) 18:55, 9 June 2016 (UTC)

See the table at the bottom of our force article, and decide exactly what it is you want to measure. "Strike" isn't a term used in mechanics, but there's force, impulse (force * time), momentum (mass * velocity), kinetic energy, and more esoteric things like jerk (d³x/dt³) and action. All such quantities are measurable (directly or indirectly), but we'll need to know which one you're interested in before we can tell you how to measure it. Tevildo (talk) 22:13, 9 June 2016 (UTC)

Measuring the change in pressure only allows you to calculate the change in volume because by Boyle's law the pressure is inversely proportional to the volume. However more information is needed about the geometry of the deformation of the football, and the elasticity of its material, before you can calculate the mechanical force of the kick. Consider instead kicking the ball straight up and having an observer record the height it reaches $h$. Then you know the energy imparted by your kick is the ball's potential energy $mgh,$ where $m$ is in kg, $g$ is 9.81 and $h$ is in metres, plus some unaccounted loss to air resistance. AllBestFaith (talk) 23:26, 9 June 2016 (UTC)

Scientific principles in engineering

Could you argue that the basic scientific principle in all the engineering disciplines are the same? 2A02:C7D:B965:D700:4058:E3A:59C2:BE6D (talk) 19:48, 9 June 2016 (UTC)

Tempting to say yes, but in practice electrical engineering is mostly concerned with stuff where Newton's laws aren't much help, whereas they are fundamental to mechanical engineering. Not too sure about the lookup table merchants, I assume they sometimes use some physics. Greglocock (talk) 00:18, 10 June 2016 (UTC)

"lookup table merchants"- I assume that's a vaguely insulting phrase for a type of engineer but I can't figure out which one? Anyway, the scientific principles are the same, even if some engineers don't use them. It's not like Newton's laws fail to work for electrical engineers :) SemanticMantis (talk) 14:55, 10 June 2016 (UTC)

Electronic engineering, I would imagine. Historically, electronic systems were adjusted (a process commonly known as "calibration", but see below) using trimmers and similar mechanical devices: today, they're built with fixed components, and the various settings required on the system to give the correct outputs for a given set of inputs are stored on the device in a lookup table. Our coverage of the issue is surprisingly thin - our article Calibration only covers calibration sensu strictu, the measurement of a parameter against a traceable standard; Adjustment (disambiguation) suggests that adjustment is the same thing as calibration, which it ain't. Tevildo (talk) 19:13, 10 June 2016 (UTC)

Lookup table merchant=Any type of engineering where the analysis is entirely defined by a set of codes typically with step by step procedures written down as well. Not electronic engineering. Incidentally SemanticMantis, obviously the laws of the universe still apply, that was probably the most redundant answer I have ever seen.Greglocock (talk) 23:13, 10 June 2016 (UTC)

I would suggest reading What Engineers Know and How They Know It (the whole book, not the wiki article). Unsurprisingly it's a series of essays on topics which engineers know something about, and how they came to know this. The chapter on flush riveting though is, surprisingly, riveting. Andy Dingley (talk) 20:02, 10 June 2016 (UTC)