# Exploro

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1. ## LETS COUNT! (Lets see if we can reach 100,000 Posts!)

My brain momentarily though the number achieved was 100 factorial. Anyway, 698
2. ## For Questions That Don't Merit Their Own Thread

In a recent project, my mechanics of materials class was given a simply supported beam with double overhanging free ends. The beam is symmetrically loaded with two identical concentrated loaded at the ends of the beam and a rectangular distributed load acting between the supports. Choosing to avoid the headache of superposition, I wrote a loading equation using singularity functions, iteratively integrating until I had the slope and deflection equations and then solved for the constants of integration. Nothing seemed to indicate anything would go wrong, and yet, when trying to show that the free ends would have the same deflection, I can't seem to get deflections that are identical. I know it is not due to the constants of integration. I repeated the calculations exhaustively, even plugging the system of equations into Wolfram Alpha's reduced echelon form calculator confirms the constants are what they should be. I'm at a loss as to what else could be wrong. Are symmetrically loaded beam with double overhangs a case where equations written with singularity functions break?
3. ## Make a wish... and have it horribly corrupted!

Granted. Maria Sirona soon exhibits a wit from which there is no escape and many a wish becomes corrupted beyond recognition. And thus Maria Sirona forever becomes known as the destroyer of dreams. I wish for snow.
4. ## Make a wish... and have it horribly corrupted!

Granted. You are instantly transported to the Moon and you experience lunar surface gravity. However, the problem is the wish granter neglected to provide you with an EVA suit. So you only enjoy the experience for a few seconds before succumbing to exposure to vacuum. I wish that Leitbur would make more albums.
5. ## Make a wish... and have it horribly corrupted!

Isn't that two wishes? But no matter, Granted on both counts You get your copy of UOS and you've successfully installed it. But sometime later, thanks to Termlink, someone hacks into your system and ganks your files. As for the 50-Shades-of-Green display, you get that too, but it is a retail display stack of books penned by E.L. James with that as the title. Oh...my wish. I wish to find my missing bottle of Sriracha Sauce.
6. ## Make a wish... and have it horribly corrupted!

Granted. But you soon find the true meaning is all the more horrifying than you realize. I wish my ginger tea actually had ginger flavor.
7. ## Why do others caramelize sugar and potassium nitrate in sugar rockets?

Shpaget is correct. According to a Wonderhowto article on making home-made solid fuel, melting the sugar improves the absorption of the Potassium Nitrate into the fuel mix.
8. ## Imperial versus metric

Acknowledged.
9. ## Imperial versus metric

In the case of the speed of light, the value is based not on arbitrary choice but rather the value arrived at by several measurement experiments conducted over the span of a century. (Textbooks generally round up to the 300,000 km/s we often cite). I imagine the same is true for the speed of sound; a value arrived to by a compendium of measurements.
10. ## Make a wish... and have it horribly corrupted!

Granted. But the price is to surrender your physical three dimensionality...you are now as flat as a piece of copy paper. As I am not feeling particularly imaginative, my wish is for a surprise. This should be interesting.
11. ## Make a wish... and have it horribly corrupted!

Granted. However the fish you receive is the dreaded Candiru! My wish is a dish made of fish; sushi that is so delish!
12. ## totm october 2020 Airplane Design Q&A

I concur. A quick excel spreadsheet done up after reading your post got positive values at AR of 9.75 and greater sticking with the value of G and L/D of 20. A positive value in the radican is positively good news. This is splendid. Thank you Mikegarrison.
13. ## totm october 2020 Airplane Design Q&A

Greetings Mike. Thank you for fielding my question. The reason for estimating the wing loading is to come up with preliminary sizing of the wings. In the edition of the book I am using, the wing's reference area is calculated with wing loading as a variable. Identifying the reference area and knowing aspect ratio will give an estimate on wing span. The value of aspect ratio I used was actually referenced from Table 4.1, where the equivalent aspect ratio for sailplanes was listed as 4.464 at best L/D. However, I defer to your feedback and will try a different aspect ratio.
14. ## totm october 2020 Airplane Design Q&A

As a starting point for an R/C glider project, I am attempting to estimate the wing loading (W/S) using an equation given in Dan Raymer's Aircraft Design: A Conceptual Approach, where wing loading is expressed a follows: W/S = [-(-G) +/- {(-G)2 - (4 CDO / pi A e)}](1/2)*[(q pi A e)/2] (An equation generator would be a nice addition to the editor) Where G is the ratio of the vertical speed and forward speed of the glider, CDO is the zero-lift drag coefficient, q is the dynamic pressure, A is the aspect ratio, and e is the Oswald Factor. Assuming a glide ratio or 20 to 1, and an airspeed of 10 m/s, the rate of decent will be approximately 0.5 m/s, thus G will be -0.04995. CDO and e are assumed to be 0.015 and 0.8 respectively. Earlier on in the text, Raymer identifies an aspect ratio for sailplanes/ gliders to be about 4.464. And lastly, q was determined to be 60 N/m2. Now. The trouble I am having is that when evaluated, the difference within the radicand is a negative value. Meaning, one can not obtain a real solution with this equation. A complex one is obtainable, but is that appropriate? Is there a different method for estimating wing loading other than that presented by Raymer.
15. ## totm october 2020 Airplane Design Q&A

The use of winglets has a lot to do with the reduction of induced drag caused by wing tip vortices, improving efficiency and performance overall. Dryden states winglets allow for 7% increase in mileage.
16. ## Random talk of food and drink

Three years ago while cycling, I came across a cooler filled with Rhubarb stalks. Taped to it was a sign that read "Free!". I don't know what compelled me to partake of what was offered, but nonetheless I did. But what does one do with stalks of Rhubarb? The answer; Cobbler. However, it should be made known that I had never made a Cobbler by that point in time before. Cooking the Rhubarb; sliced into manageable chunks, was easy. The stalk chunks, sugar, and water was cooked in a sauce pan to prepare the filling. The jam-like substance left in the pan was delicious. I was expecting something tart but was delightfully surprised by the sweetness. Wish I had crackers to have spread it upon. Now the crust was perhaps the most unorthodox for anyone who has made a Cobbler. I saw a recipe online that used yellow cake mix; drenched in melted butter, as the crust. That appealed to my culinary laziness. But it worked. There was enough filling and cake-mix to make two cobblers that day. Ah...fun times. I am happy to conclude my recollection by stating my culinary experiment of three years ago was a delectable success.
17. ## Would You Want A Scifi Spaceship If It Only Had Manual Controls?

To an extent. A post by WolfOdrade on Stack Exchange's Science Fiction and Fantasy entitled "In the Dune series, why are they not using computers and programming related technologies?" states that in the original Dune, basic computer systems would be legal so long as they do not emulate the human mind.

-1 (0-1=-1)
19. ## For Questions That Don't Merit Their Own Thread

I was wondering if my understanding of an analog Absolute Magnetic Encoder is sound. In a project this last semester we used such a sensor for a wind vane. The signal output range was between 0 volts and 5 volts. As the encoder rotated through 360 degrees the voltage would increase to the maximum output and then reset to zero. While that was easy to understand the relationship between voltage and position, the data sheet never made clear as to how the sensor was generating the signal. But the project also had us working with Hall Effect sensors, which had me thinking. The magnitude of Hall Voltage, Vh, is directly proportional to the magnetic flux acting on the conductor of the sensor. Thus is is safe to assume that it is the magnetic flux that is changing as encoder rotates, and in turn, causes the change in the voltage signal of the encoder?
20. ## Liquids that don't boil at 0 ATM.

I was speaking with someone who works at a company that uses Ferrofluid as the seal for vacuum chambers among other things. While my knowledge of this type of material is extremely limited, the fact it is used for applications at zero atmosphere suggests using ferrofluid could accomplish your airlock concept.
21. ## Make a wish... and have it horribly corrupted!

Granted. However the Kerbal Space Center is set up in your hometown. Due to the Kerbal's penchant for unscheduled spacecraft disassembly and catastrophic failures, your hometown soon becomes a cratered ruin. I wish for that KSP is returned to it's computer realm so Robonoise's town will no long be destroyed.
22. ## Make a wish... and have it horribly corrupted!

Granted. You received coins made from a 0.3 mm drill bit, but how this profits you is anyone's guess. I wish for a cure to a sore throat.
23. ## Make a wish... and have it horribly corrupted!

...So what do you want?
24. ## Make a wish... and have it horribly corrupted!

Granted. You sense the speech is over. However you realize that this is only so because you've gone deaf. I've lost my hat. So I wish for a new hat.
25. ## Make a wish... and have it horribly corrupted!

Granted, however you'll live to see the heat death of the universe. Bored out of your mind from experiencing eons of nothingness and having nothing to look forward but even more nothingness, you wish for sweet release. On the topic of things that are cold, I wish it were winter.
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