Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
It might be better to just get another gerbil.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                                                                                                                         

Drop a Penny Skyscraper Vending Machine

A Vending Machine that Drops Pennies from the Top of Skyscrapers
  (+21, -1)(+21, -1)
(+21, -1)
  [vote for,
against]

A very simple idea. We've all wanted to drop a penny from the top of a skyscraper. How much would we be willing to pay for the privilege? Vending machines could be installed in the observation deck of a skyscraper, which would allow us to do exactly that. For the reasonable price of 51 cents, this vending machine would send that penny rolling down a slot through the wall, and out over the unsuspecting city. The observation deck gets the additional revenue (from the 50 cents it keeps), and we get to fulfill a childhood fantasy. A photo or a DVD of your penny striking the ground would be available for an additional fee.
DonBirnam, Feb 05 2004

Terminal velocity of a penny http://www.gantless.com/paper.html
20 - 45 mph according to this. [Worldgineer, Oct 04 2004, last modified Oct 21 2004]

Jim Carson: Monday morning armchair physicist http://www.jimcarso...chives/000148.shtml
Looking at the way a penny drops. 23.6 mph to 73.3 mph. He also mentions the TV programme 'Mythbusters' where they fired a penny at somebody's backside at a speed of 64mph with no major consequences. [st3f, Oct 04 2004, last modified Oct 21 2004]

Thar She Blows! http://msnbc.msn.com/id/4096586/
I wonder if it will be friends with me. [gnomethang, Oct 04 2004, last modified Sep 29 2006]

BalloonDrop.com BalloonDrop_2ecom
[Shameless plug] [Klaatu, Aug 28 2008]

[link]






       I bunned this, but will only keep it assuming one of two things:
1) You have a fenced off penny landing area, possibly containing things like watermellons and glass bottles to destroy.
Or:
2) You move this to the public: evil category.
Worldgineer, Feb 05 2004
  

       I want my photo in monochrome, just a slow enough shutter speed for some blur, then a strobe to freeze it on the bounce.
normzone, Feb 05 2004
  

       How about adding a target zone with something breakable in the center. There would be ten second count down and a warning siren to attract a crowd.
duroncrush, Feb 05 2004
  

       I do like the addition of breakable targets and a target area. The best I could think of was cheap parking near the building.
DonBirnam, Feb 05 2004
  

       I'm assuming the attraction is the myth that a penny falling from a skyscraper will reach lethal velocities, which is not true at all. While the zero-drag (vacuum) speed would be quite high, since the penny falls through air, we can't assume vacuum. Terminal velocity of a penny in air (this is the point where drag=weight) is roughly 65 mph, give or take a few. Getting hit wouldn't hurt any more than if someone had thrown it really hard.
Freefall, Feb 05 2004
  

       Can there be another shute for frozen peas? I've heard that if you drop one off the Eiffel tower it could kill someone. When I visited the Eiffel tower as a child I was very uncomfortable walking around underneath it in case some one was testing the whole pois theory.
hazel, Feb 05 2004
  

       //Getting hit wouldn't hurt any more than if someone had thrown it really hard//   

       You first.
k_sra, Feb 05 2004
  

       <puts umbrella up>
po, Feb 05 2004
  

       + for the research ... although that's right out of keeping with the bakery as a whole. An idea with proof... what is the world coming to!?   

       // whole pois theory // what is she on this evening?
jonthegeologist, Feb 05 2004
  

       But 45 mph accidents [scout] involve collision between two cars, one of which you are in. You are surrounded by a metal cage which can absorb the impact. Falling off a skyscraper involves a collision between your (soft) body and the (hard) pavement.
hazel, Feb 05 2004
  

       Actually, it's closer to 200 m.p.h. not enough to "go, like, fifty feet into the ground" but enought to go like through a skull (for example).   

       Oh, I see, a tall building is "at least 40' " according to the link. Here in NYC that's called a speed bump. Also, terminal velocity is the max it can reach (with the air drag) not what it gets to at the bottom. Your penny is accelerating until it hits something. It reaches terminal velocity after approximately 1200 feet, I believe (we did this calculation when I was wee one in high school and I'm not really up to doing over now)
username, Feb 05 2004
  

       Terminal velocity is different for different objects, depending mainly on the shape texture and weight of an object.
Worldgineer, Feb 05 2004
  

       Indian head pennies, or Lincoln pennies?
Shz, Feb 05 2004
  

       //shape texture and weight of an object//   

       <looks critically at [Worldgineer]'s head>
k_sra, Feb 05 2004
  

       I was wondering how older heavier pennies would fare in this test. Also, would the slot it rolls down spin the penny fast enough so that it has a gyroscopic effect, causing it not to tumble? What if we could drop dollar coins? So many questions...
DonBirnam, Feb 05 2004
  

       Could it have a solid steel plate to land on and an automatic retrieval service? It could be like the penny-mashing devices at tourist traps. Take your deformed penny with you as a keepsake from your venture to the city center.
Letsbuildafort, Feb 05 2004
  

       Worldgineer's link is interesting. Unfortunately, despite taking a series of measurements, the final conclusions look as though they are reached using intuition, which is a pity. The experimenters look at different modes of falling but I'm not convinced that they cover the full range.   

       The terminal velocity of a penny should vary greatly depending on how it falls. A penny falling completely flat (unstable and unlikely but theoretically possible) shows large flat surface to the air and would fall slowly. Picture driving along with a billboard secured to the front of your car and try to imagine what your top speed would be.   

       Conversely a penny falling on edge (more possible, fairly stable and more likely over a long drop). It now exposes only its edge as a drag surface and will have a much higher terminal velocity. Picture the same advertising hoarding stuck flat to the side or roof of your car.   

       Here are some numbers for a UK penny:
Thickness: 1.7mm
Diameter: 20.0mm
  

       Area presented edge on: 34.0mm^2
Area presented face on: 314.1mm^2
Added to this the edge profile slopes away reducing drag whereas the face end abruptly at the edge of the coin.
  

       Since drag is proportional to surface area I would expect a variation of at the very least a factor of nine in the drag, possibly many more times this as shape is very important in aerodynamics. (Does anyone have coefficients of drag for a flat disk edge on and face on?).   

       OK, my turn to pluck some results out of the air. Say the drag is 20x more flat then on edge, I would expect the fast terminal velocity to be about four or times faster then the slowest. Unfortunately this doesn't give me the much of an idea of where the range starts and finishes. It could be 10-50mph or 20-100mph. Either way, I think that the range would be bigger than that stated in Worldgineer's link.   

       Wow. That rambled on longer than I expected. Let me say that I think it's a great idea and I'd love to look at the bottom end of the penny drop (side on through reinforced glass) to see the coins bouncing off concrete. (goes off to find website with some more numbers on it)
st3f, Feb 05 2004
  

       I like this too. Similarly when you take your car to the scrapyard, they shouldn't just put it in a pile with the others, they should use some sort of catapault to 'drive' it into another car.
hippo, Feb 05 2004
  

       This would be good in Las Vegas with a silver dollar slot machine on the bottom floor of a tall building. Every once in a while a player would get (un)lucky and be hit by a torrent of heavy coins from the roof.
FarmerJohn, Feb 05 2004
  

       [st3f] I sheepishly admit not reading my link before posting it. Glancing at it again it seems like a high-school level experiment that was poorly planned and therefore went awry, and instead of admitting they didn't consider the theory before designing the experiment they just gave estimates that fit their observations.   

       I liked it because it had experimental data, and I can't find any elsewhere.
Worldgineer, Feb 05 2004
  

       Anyway, could we choose what it landed on? Lots of people seem to like the breakable target. I think jello or silly putty would be even cooler.
username, Feb 05 2004
  

       It could be a lot of fun to put some ballistic gel samples in the target area. If yours hits the ballistic gel, you could buy that in the gift shop.
DonBirnam, Feb 05 2004
  

       //Can there be another shute for frozen peas? I've heard that if you drop one off the Eiffel tower it could kill someone. When I visited the Eiffel tower as a child I was very uncomfortable walking around underneath it in case some one was testing the whole pois theory.//   

       Considering the Eiffel Tower curves as it goes up, a frozen pea dropped from the top would hit the structure before it reached the ground.
GenYus, Feb 05 2004
  

       // Well, I for one don't believe all of that "terminal velocity" stuff. // [scout]   

       Scout, this is science. your beliefs are irrelevant. I'd gladly stand at the foot of any skyscraper while someone dumps a handful of pennies off the edge, just don't ask me to look up...my eyes are softer than my skull. I'll charge a dollar for every penny that manages to hit me, as I expect it to sting quite a bit. Terminal velocity is different for different objects. A skydiver (terminal velocity of 120 mph, approx, and I should know...) will fall faster than a penny (terminal velocity of between 25 and 75 mph, approximately, depending on how it's falling) because the skydiver has less drag per unit mass than the penny. Edge-on, unless the penny is spinning, will actually be a very unstable position.
Freefall, Feb 05 2004
  

       If you're saying fluid dynamics isn't science, then it's nice to meet you Mr. Hawking.
Worldgineer, Feb 05 2004
  

       It does curve [GenYus] but it has an open structure so you could get a pea through the ironwork of the tower. Or you just throw it out a bit. Alternatively you could throw your pea down the hole in the middle of the tower, but this is only on the first stage and probably wouldn't be high enough to kill.
hazel, Feb 06 2004
  

       // //this is science// //   

       Not yet. So far just a lot of highly informed conjecture. There's potential for some real science here, but that'd spoil the fun. Meanwhile, I'll contribute the following. A BB (solid copper sphere about, what, 3-4mm?), shot into the air with a Daisy spring rifle, streaks upward, disappears for a few seconds, and streaks back down. It can be safely bounced off the palm of one's hand. Stings like a wasp, but does not break the skin. (Please wear safety glasses if you try this at home). I have no idea how high the BB goes, but the combined drag on the way up and down is probably near that encountered on a skyscraper. I never had the guts to put my hand over the end of the rifle, to compare the impact straight out of the muzzle, but from what it did to plywood at 10 ft, and that unfortunate bluejay, I bet it breaks the skin.   

       I'll stand under the penny.
oxen crossing, Feb 06 2004
  

       Every drop of rain that falls...   

       (+)
Jinbish, Feb 06 2004
  

       Consider this: that penny has passed through many hands (and probably some kid's mouth). If it only nicks the skin, think of the germs entering your bloodstream.   

       Won't kill you, indeed.   

       "It's not the bullet that kills you; it's the hole" -- Laurie Anderson
username, Feb 06 2004
  

       //The best I could think of was cheap parking near the building.//   

       That was what got my vote.
Detly, Feb 06 2004
  

       Hmm. I hadn't fully considered non-coins. Pricing would have to be determined for other objects, probably based on damage, liability, etc. I would look forward to the annual bowling ball day, although I think I'd want to show up early. I wouldn't want to try to run into the building after things got started.
DonBirnam, Feb 06 2004
  

       feefall Can I drop a roll of pennies on you? it's only a handful! There's more than just velocity to consider. One penny would bounce off your head a roll might kill you.
duroncrush, Feb 06 2004
  

       Same with a bowling ball. Your point was...?
Worldgineer, Feb 06 2004
  

       Sure you can drop a roll of pennies on me, if you take it out of the wrapper first. $0.50 worth of still-rolled pennies probably could kill someone.
Freefall, Feb 06 2004
  

       You have a 'nonfunctioning-copy-machine Day' by chance?
RayfordSteele, Feb 06 2004
  

       Save yourself the money. Throw a penny in the air and watch it land. Pretty exciting isn't it? Take a souvenir picture too, if you want.
waugsqueke, Feb 06 2004
  

       Didn't David Letterman already exploit this Idea to no end?   

       And by the way, a watermelon or a frozen turkey exploding on impact are two of the funniest sights you may ever come across in your lifetime
WordUp, Feb 07 2004
  

       I bet that whale that exploded in downtown Tainan, Taiwan would make the top 3 as well [Wordup]! (Linky)
gnomethang, Feb 07 2004
  

       going back to the idea of breakable targets, why don't we all bring pictures and objects of things we would like to smash. distasteful vases, pictures of ex-lovers, windows computers, etc. and smash those! i foresee hours of endless funa nd amusment.
bezzzie1, Feb 07 2004
  

       Having ridden through a hailstorm on a motorcycle wearing an open faced crashe helmet, I can agree that whilst they may not kill, they smart some. As an added bonus, your face turns a wonderfully dappled red/white combo. With respect to the subject matter, whilst I can see that the shape of a penny does not lend itself to acheiving a high terminal velocity, I'd not like one to land edge on on my noggin, even at a 'mere' 70 mph. perhaps you could replace the penny dispenser with a water balloon dispenser, it would add a frisson of excitement to the daily commute past the ESB - and for the dispensee - they joy of a direct hit would be hard to beat
p1stonbroke, Feb 07 2004
  

       Sounds fun!
spacecadet, Feb 07 2004
  

       Can I spend more and drop burning balls of acetone? the fireballs would completly disapear before hitting the ground but not before creating a pretty fire-waterfall effect.
johnmeacham, Feb 08 2004
  

       You people need more to do.
Mighty piffle, Feb 08 2004
  

       According to Dennis Thompson (dthompson@lerc.nasa.gov), safety testing at NASA's Zero Gravity Research Center in Cleveland concluded that coins falling from a height of 510' in air achieve a terminal velocity that is too low to seriously injure a person it strikes, much less bury itself in concrete.   

       They should place lifelike dummies filled with red goo on the ground, so they explode on the onlookers when hit by pennies.
Deadlock'd, Feb 09 2004
  

       We've established that the penny couldn't kill someone, but I bet it still could cause injury or property damage. Suppose it hit a person in the eye who was looking up, or landed right on the windshield of a car.   

       I would think you'd need an enclosed chute for the penny to fall in, it could be attached to side of the building. This would actually open up other revenue streams, for instance charge someone extra to put an item of their choice at the bottom of the chute to be hit by a falling penny, etc.
krelnik, Feb 15 2004
  

       I'll bet if I bent a copper penny in half, it would improve the aerodynamic characterstics quite a bit--maybe enough to overcome the flutter problem. Hmmm...
booleanfool, Apr 04 2004
  

       A penny dropping off a skyscraper isn't exactly an amazing sight. It'll hit the ground at approximately 25 mph, if it even makes it to the ground. Updrafts send many pennies to the roofs of other buildings, or to setback roofs on the same building.
whatastrangeperson, Apr 04 2004
  

       The next time I go to Chicago, remind me to snoop around on the roofs for some change.
RayfordSteele, Apr 04 2004
  

       There should be a wishing well on the landing area. If your penny drops into 1 metre diameter wishing well you can consider yourself lucky. And you are granted a wish. Penny for your thoughts?
Pellepeloton, Sep 27 2006
  

       Theres a slight problem with winds but I would put my 51 cents up just for the heck of it. I personally would love a building to build a drop garden which has an assortment of drops daily. Such as paintballs, frozen poultry, bowlingballs, various flaming objects, oboes, and cable modems.
baslisks, Sep 27 2006
  

       Evacuated glass chute?
GutPunchLullabies, Sep 28 2006
  

       So this is a wishing cliff?
Loris, Sep 28 2006
  

       sure. Cliffs>Wells.
baslisks, Sep 29 2006
  

       Oh, I couldn't resist the challenge.   

       As far as I can tell, the terminal velocity works out around 65m/s, or 139 mph. That's for the coin falling edge-on, for which the Cd comes out at about 0.5.   

       Nope, I wouldn't stand under that.
Frankx, Sep 29 2006
  

       in order to fall edge first, one area of the edge will have to be significantly heavier than the trailing, as it is a coin will spin. look at it this way, if u try really hard to stand a penny on its edge it may stand up, but you cannot stand a penny on the air pressure of its terminal velocity. 139mph wind will quickly turn a penny on its side starting the spin. the terminal velocity of 25-70 exactly that - terminal velocity.
fairlanecobra, Sep 29 2006
  

       Put the cheap parking on top of the skyscraper, each time someone deposits a penny for a ticket the car which has been there the longest gets launched off the top onto the ground below.   

       You never run out of spaces and you get a free tourist attraction.
mecotterill, Aug 22 2008
  

       Letterman always fenced the area off- boring! Old school!   

       Instead, make it $5.00 to drop a penny, but let people throw them. Then, use $4.50 for the insurance, and still get .50 for maintenance. And, sell photos of the impact (especially on unsuspecting pedestrians, taxis, hot dog stands) to boot.
Bcrosby, Aug 22 2008
  

       Sweeet! +
simonj, Aug 28 2008
  

       //in order to fall edge first, one area of the edge will have to be significantly heavier than the trailing, as it is a coin will spin.//   

       Unless you span it like a wheel as you threw it, of course. I don't know how much spin you'd need to resist tumbling, but it's pretty easy to add 'flat' spin to something as you throw it - skimming stones on water works because of this.
Loris, Aug 29 2008
  

       I'm guessing friction will stop the thing spinning fairly quickly. But I have no science to prove it.
Worldgineer, Aug 29 2008
  

       When I first saw this I figured that the penny would be encased in some sort of tube going the full height of the building so that there would be no wind drag (other than the air in the tube)
Jscotty, Aug 29 2008
  

       [Jscotty] Now there's an idea. Except evacuate* the tube. That'll send up some serious sparks when they hit the pavement**.   

       * Why isn't this word spelled "evacuuate"?   

       **pavement section inside of evacuated chamber at bottom, along with (vacuum-space appropriate) objects you'd like to destroy.
Worldgineer, Sep 02 2008
  

       Put it in a vaccuum chamber with a soft target and a video camera at bottom.
Cedar Park, Sep 02 2008
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle