# Search results

1. ### Saw characteristics influencing efficiency in sawing steel?

Hello, I am having a headache to try understand a possibly simple real-world problem: efficiency (as in number of strokes/cumulative length needed) to saw steel, assuming a constant sawing length per stroke and a known steel sectional area. I began to think about the few assumptions I assume...
2. ### Finding the acoustic point in a valley

Hello, I have a practical problem, I'd like to find the "best" spot to hear sounds in a valley (forgive me if "acoustic point" isn't an appropriate term, I just couldn't come up with anything better and scrolling an acoustics text didn't help), or at least a non-blind spot (one which instead...
3. ### Water wicking up porous media and air humidity ?

Hello, I'd like to know which of these 3 example I sketched would have a steadier and higher air humidity at measuring point, assuming same conditions (except those illustrated as different, like porous media thickness and measuring point), water level and air turbulence within larger container...
4. ### Maximum light intensity underwater during seasons?

Hi, I was thinking if maximum light intensity underwater during seasons changes somehow. I firstly thought about considering monthly solar irradiance (http://neo.sci.gsfc.nasa.gov/view.php?datasetId=CERES_INSOL_M) however I thought this would have been biased at certain latitudes due to...
5. ### Where could I look for down-to-earth X-ray facts?

Hello, I'd like to know which book or papers I'd read to understand, possibly without too rigorous mathematics knowledge, how do photons like X-rays or gamma ones reflect off surfaces and attenuate through solids or generally speaking, facts about how do they interact with the real world. So...
6. ### Is a motionless liquid-floating object possible?

1. Homework Statement Do you think it's possible for an object to be relatively motionless if floating on rippled water surface? Could this be achieved by have it float inside one (or several nested) water/oil-containing containers? 2. Homework Equations ES = - n2(k-m)2 Lucassen's...
7. ### B Visual proof of being at altitude?

Hi, this may seem like an odd questions to most of you but I'd still like to ask what could be some visual proofs of being at high altitude, say 10,000 feet above sea level. While any said proof is not extremely rigorous or untamperable and probably little more than a showy capture to add to...
8. ### Calculating air pressure from altitude, RH and temperature?

Homework Statement [/B] This is a practical problem, no homework question. I'd like to determine pressure (and O2 partial pressure) at altitude, yet following a more realistic real-world calc including measured data like relative humidity (RH) and temperature at that altitude, yet all I can...
9. ### Is it possible to estimate a light source wattage remotely?

I'd like to know if it's possible to roughly estimate a light source wattage remotely, knowing the distance and perhaps estimating that at such a distance it's still above the minimum human recognizable threshold at night (in a light polluted area). Maybe using a DSLR camera could help by...
10. ### Water evaporation, temperature, wind and heat capacity?

Hi, I'd like to know how I'd put together, either elegantly or at least in physical terms, that surely water evaporation in a large pool of V volume and S surface is influenced by wind (increased by it as opposed to having side barriers), temperature (increased by direct sunlight as opposed to...
11. ### Capillary action speed formula?

Hi, I was looking for a formula to describe capillary action speed in a medium. On wikipedia (https://en.wikipedia.org/wiki/Capillary_action) I came across a formula which describes the cumulative volume of a liquid drawn by capillary action after time t where V is cumulative volume, A is...
12. ### Maximum useful matrix size for radiation counting?

Hi, I'd like to know if there is a maximum matrix size after which radiation counting (using a scintillator/photomultiplier) on a flat paper sample doesn't improve or is not significant. Specifically this would refer to radiochromatograms, or chromatography strips of radioactive samples. If...