Ask and answer stupid questions here! - Page 365
| Forum Index > General Forum |
|
Simberto
Germany11839 Posts
| ||
|
538
Hungary3932 Posts
On November 10 2015 21:47 SoSexy wrote: Is is possible to put something in front of a bullet in order to make it loose so much momentum that it will just bounce off without harm once hitting you? Not thinking about bulletproof vest, but more to something like a foam block, where you could actually see the bullet slowing and hitting you at the speed of a drunk fly I don't see why not. See this video for an example of a bullet slown down to speeds small enough to not penetrate a balloon. However, I'd guess it's very hard to achieve consistent exit speeds while setting up such a device, and even then, it would only work with one specific kind of bullet and gun. You can't really create a "magic vest" which makes every projectile pass through, but only with non-harmful speeds. | ||
|
KwarK
United States43989 Posts
On November 10 2015 21:47 SoSexy wrote: Is is possible to put something in front of a bullet in order to make it loose so much momentum that it will just bounce off without harm once hitting you? Not thinking about bulletproof vest, but more to something like a foam block, where you could actually see the bullet slowing and hitting you at the speed of a drunk fly about three feet of water will do the trick | ||
|
ThomasjServo
15244 Posts
On November 11 2015 01:56 KwarK wrote: about three feet of water will do the trick Note to self, in case of gun fight in fancy restaurant with large fish tanks ala Mission Impossible one. That is of course if I don't have explosive chewing gum. | ||
|
oGoZenob
France1503 Posts
On November 11 2015 01:56 KwarK wrote: about three feet of water will do the trick actually when it comes to water and bullet, the slowest one lose less momentum as they go through water, and so go further. there was a mythbuster episode when they tested huge guns shooting at an underwater target. The most powerfull guns had bullet that went so fast that the impact with water completely destroyed the bullet without touching anything, while small caliber kept their integrity given that they packed far less energy on impact. So if you want to shoot someone in the water, use a small handgun ^^ | ||
|
AbouSV
Germany1278 Posts
But this is also different if you are shooting from inside the water or from the air, into the water. Just don't shoot someone in the water, either wait for him to get out, or watch him drown. | ||
|
marvellosity
United Kingdom36161 Posts
On November 12 2015 19:10 AbouSV wrote: The water being a non-Newtonian fluid (it gets harder when hit faster), this is not surprising. But this is also different if you are shooting from inside the water or from the air, into the water. Just don't shoot someone in the water, either wait for him to get out, or watch him drown. Truly life advice to live by although the wiki seems to suggest water is a newtonian fluid? | ||
|
AbouSV
Germany1278 Posts
To quote the related page about non-newtonian fluid (I liked the Newtonians ones) : 'Viscosity is constant. Stress depends on normal and shear strain rates and also the pressure applied on it' i.e. you can jump in water from air if you don't 'press' it too much, but if the pressure applied to the water is too high (coming too fast, or too wide), the water will behave like concrete for the impact. | ||
|
Cascade
Australia5405 Posts
On November 12 2015 19:43 AbouSV wrote: Under 'normal' condition, water is indeed newtonian. To quote the related page about non-newtonian fluid (I liked the Newtonians ones) : 'Viscosity is constant. Stress depends on normal and shear strain rates and also the pressure applied on it' i.e. you can jump in water from air if you don't 'press' it too much, but if the pressure applied to the water is too high (coming too fast, or too wide), the water will behave like concrete for the impact. So you can make underwater bullets that are long and pointy, and they will travel better under water, as they displace the water better without compressing it as much? | ||
|
Simberto
Germany11839 Posts
| ||
|
Cascade
Australia5405 Posts
On November 12 2015 21:02 Simberto wrote: Like, for example, a harpoon? Such as something along those lines, yes. ![]() | ||
|
AbouSV
Germany1278 Posts
| ||
|
oGoZenob
France1503 Posts
On November 12 2015 21:02 Simberto wrote: Like, for example, a harpoon? a harpoon works because it's extremely slow compared to a bullet, so the water still has a newtoniam fluid behavior at this energy ![]() | ||
|
Cascade
Australia5405 Posts
This seems to break down to some extent at close to sound speed... Commercial airliners still have the blunt front and sharp back tip, while military (supersonic) aircrafts tend to have a sharp tip. Bullets (2000-4000km/h) travel well above sound speed in air (1400km/h or so), but less in water (~5500km/h). So judging from that, I'd have guess that a round-nosed and sharp-ended shape of bullet would do fine underwater. But yeah, maybe water isn't the same as air after all. ![]() | ||
|
Oshuy
Netherlands529 Posts
On November 12 2015 23:45 Cascade wrote: I wonder though... Naively, the best shape for low resistance is a sharp tip that bends back at as thin angle as possible, which will decrease the speed/acceleration with which it has to displace the water/air in front of it. Yet, aerodynamic or waterdynamic (what do you call it?) things tend to be blunt and rounded at the front, and then a sharp tip at the back. I understand this is due to decreasing drag by maintaining laminar flow: the main problem seems to be to allow a smooth way for the liquid/gas to fill up the void behind you, rather than displacing in front of you. This seems to break down to some extent at close to sound speed... Commercial airliners still have the blunt front and sharp back tip, while military (supersonic) aircrafts tend to have a sharp tip. Bullets (2000-4000km/h) travel well above sound speed in air (1400km/h or so), but less in water (~5500km/h). So judging from that, I'd have guess that a round-nosed and sharp-ended shape of bullet would do fine underwater. But yeah, maybe water isn't the same as air after all. ![]() One way to travel fast under water is supercavitation, roughly to create a bubble of water vapor in which you travel instead of hitting liquid water. Allows underwater firearms to be effective up to 20m or so and torpedoes to get to ~500km/h. Another solution is to fire needles instead of bullets. Round-nosed harpoons work because they are slow/heavy enough, but they are for shorter range anyway. | ||
|
waffelz
Germany711 Posts
I have fallen in love with this monitor, but the QA for it is so poor, everyone I received so far was worse than the former (gone from dead pixel in the centre, to dead pixel and noticeable cross-hatching to dead pixel and cross-hatching all across the screen), so I would like to try out 5 monitors at once and keep the best one if it is to my liking. It seems like the only realistic way to get a proper monitor of this model. I can’t imagine amazon being keen on me buying for 3k+, but only keeping 1/8th of that worth though… there already where cases of people getting blocked from amazon because they returned to much stuff. It was something like always keeping the stuff for as long as possible, then returning it and buying the same thing again as far as I know/about 50% return-rate, but still. My return-rate is very low so far, but the sheer amount of money that would be on the table here scares me a bit. Even though I returned those monitors pretty much ASAP, I still assume it causes amazon a lot of troubles (checking the stuff, repackaging etc.) | ||
|
Cascade
Australia5405 Posts
On November 14 2015 10:24 waffelz wrote: So, any idea how amazon would feel about me buying about 5 monitors worth about 2k, just to keep one? Also given that I already bought 3 separately and I already returned the first 2 and am about to return the third as well. I have fallen in love with this monitor, but the QA for it is so poor, everyone I received so far was worse than the former (gone from dead pixel in the centre, to dead pixel and noticeable cross-hatching to dead pixel and cross-hatching all across the screen), so I would like to try out 5 monitors at once and keep the best one if it is to my liking. It seems like the only realistic way to get a proper monitor of this model. I can’t imagine amazon being keen on me buying for 3k+, but only keeping 1/8th of that worth though… there already where cases of people getting blocked from amazon because they returned to much stuff. It was something like always keeping the stuff for as long as possible, then returning it and buying the same thing again as far as I know/about 50% return-rate, but still. My return-rate is very low so far, but the sheer amount of money that would be on the table here scares me a bit. Even though I returned those monitors pretty much ASAP, I still assume it causes amazon a lot of troubles (checking the stuff, repackaging etc.) Have you tried contacting them and explain your problem? | ||
|
waffelz
Germany711 Posts
On November 14 2015 20:22 Cascade wrote: Have you tried contacting them and explain your problem? I send the first monitor back as defective since I noticed the dead pixel to late/the pixel died after the 2 weeks. I am pretty sure they are aware of the horribly QA for that monitor. Asking them: “Hey, I am about to buy 5 of your monitors with the sole intend to only keep one at max. If none of them is to my standards, I won’t keep any of them and send them all back. Are we good here?” will most likely simply give me a standardized answer like “If it is in the 2 weeks period, you can send every article back without any problem”. Dead Pixels would be an easy case since amazon is very accommodating when it comes to that, but I think cross-hatching they don’t care about (even most manufacturers don’t rate that as a defect). Also there are a number of other problems with this monitor you can run into if you get one of the bad panels. Heavy backlight-bleed, clouding, uneven colours/light… some of that stuff isn’t under warranty either. As a side question: What does amazon actually do with stuff that get returned (not send back as defective)? It is already used, but I assume they want to sell it again for full price. Do they have to send it back to the manufacturer so he checks and repacks it? Or are they forced to sell it at a discount from now? | ||
|
Cascade
Australia5405 Posts
On November 14 2015 21:33 waffelz wrote: I send the first monitor back as defective since I noticed the dead pixel to late/the pixel died after the 2 weeks. I am pretty sure they are aware of the horribly QA for that monitor. Asking them: “Hey, I am about to buy 5 of your monitors with the sole intend to only keep one at max. If none of them is to my standards, I won’t keep any of them and send them all back. Are we good here?” will most likely simply give me a standardized answer like “If it is in the 2 weeks period, you can send every article back without any problem”. Dead Pixels would be an easy case since amazon is very accommodating when it comes to that, but I think cross-hatching they don’t care about (even most manufacturers don’t rate that as a defect). Also there are a number of other problems with this monitor you can run into if you get one of the bad panels. Heavy backlight-bleed, clouding, uneven colours/light… some of that stuff isn’t under warranty either. As a side question: What does amazon actually do with stuff that get returned (not send back as defective)? It is already used, but I assume they want to sell it again for full price. Do they have to send it back to the manufacturer so he checks and repacks it? Or are they forced to sell it at a discount from now? If they tell you that you can send them all back, then what is the problem? If you are worried they'll complain anyway, then write down the name of their representative on the phone, and you can say that this guy said at that time that you could do that. They usually save the calls, so they can go back and check. Also I don't understand why you don't get a monitor without all these problems, but that's a different story. ![]() And regarding the side question, they'll probably sell it reduced. I just today bought a fridge slightly reduced because it was a return. I'd guess they do the same with screens. | ||
|
waffelz
Germany711 Posts
On November 14 2015 23:13 Cascade wrote: If they tell you that you can send them all back, then what is the problem? If you are worried they'll complain anyway, then write down the name of their representative on the phone, and you can say that this guy said at that time that you could do that. They usually save the calls, so they can go back and check. Yeah you are right. Asking probably won't help, but it definitely won’t hurt either. The discount thing discourages me even more though as it means they will lose money in the process. Also I don't understand why you don't get a monitor without all these problems, but that's a different story. ![]() Trust me, even though I raged hard about the problems, I still really want this monitor. Having checked out other monitors, this one is simply the best. Perfect merge of good colour, awesome black and refresh rate. More than amazing in general and well suited for gaming. It fucking spoiled me in terms of image quality, which is why I am willed to dig through 8 monitors just to get one that’s ok ![]() | ||
| ||


