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
Fewer ducks than estimates indicate.

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.



skydiving in a car without parachute

  [vote for,

Construct a giant ramp. At the top it will be nearly vertical.Car will land on the ramp at this point. It will be in vertical position. Its tyres will gently brush the ramp. Ramps slope will gradually go on decreasing as car moves along the ramp downward. At the end of ramp slope will be near horizintal, where car will exit the ramp. If constructed properly, skydiver should not feel any impact. Car will have control surfaces like rudder, flaps etc so that it can be precisely navigated to the top edge of ramp.

It will be interesting to calulate the required height of ramp.I think max "g" humans can survive is 5. That should be the key. Terminal velocity of car will be 120 mph. In other words cars speed will be 120 mph when it will land on the ramp.

VJW, Jan 30 2012

Alternative_20Tube_...for_20dare_20devils Tangentially related idea [hippo, Jan 30 2012]


       No matter how gently the ramp curves from vertical to horizontal, the g-forces involved will be severe. It would also have to be a damned accurate skydrive to hit the top of the ramp with the car oriented properly. Any variation that resulted in the car hitting the slope rather than the vertical would lead to a catastrophic impact. You're probably also going to need a specially modified car with incredibly stiff suspension and bolstered steering like a top-fuel dragster. This, in turn, would require a perfectly smooth ramp, else the tiniest bump would send the car flying.   

       Try it out with a Hot Wheels track and you'll see what I mean. It will probably take dozens of attempts before it works the way you want it to; with a real car, carrying real passengers, you only get one try.
Alterother, Jan 30 2012

       It's not impossible. However, the terminal velocity of a car, if nose-down, will be well over 120mph - I'd guess 150-200mph, depending on the car. A Volvo might be good (boxy), or better yet a caravan or similar.   

       So, assuming a t.v. of 150mph (70m/s), and a maximum G of 5 (50m/s/s which is very conservative), you'll want to curve out over about a 1.5 second period, or about 50-60m of vertical distance.   

       So, this is by no means un-doable, if you could hit the start of the ramp accurately.   

       Actually, there are several skydivers who have proposed to land parachuteless in a wingsuit, using a similar arrangement.
MaxwellBuchanan, Jan 30 2012

       If the car is aerodynamic enough to be able to not tumble madly out of control as it falls, its terminal velocity may be somewhat higher than 120mph.

Let's say though that the vertical velocity of the car is 50 metres/s. The velocity of a decellerating body is given by v=u-at. If 5g is allowed and g=10, and we want the car to come to rest then (only looking at the vertical component of the car's motion) this becomes 0=50-50x1 so t=1 and all this happens in 1 second (that seems very quick! - have I got this wrong?). Then putting t=1 into s=ut-0.5at^2 = 50-0.5x50 gives us 25m for the height of the ramp.

[EDIT: Evidently [Max-B] types faster than I do]
hippo, Jan 30 2012

       //1 second (that seems very quick! - have I got this wrong?)// No, it's right. A regular parachute fully deploys in maybe 2 seconds; a reserve chute will deploy in something like 1 second; in both cases, the skydiver's vertical velocity is near zero by the time the chute's fully deployed. Most of the braking happens during the later stages of deployment, so the peak deceleration is actually a bit higher. A steady 1 second deceleration at 5G would be comfortable.
MaxwellBuchanan, Jan 30 2012

       There is definitely a theme park roller-coaster type ride that does exactly this, albeit that the vehicle is attached to rails. The humans seem to survive the G absolutely fine. Forgotten where it is though and damned if I can find it through Google...
goff, Jan 30 2012

       Drop Of Doom at West Edmonton Mall is an eight story free-fall with rapid decelleration.   

       <side story> A hotel my mom worked at handed out travel coupon booklets to new guests. when the new shipment of booklets arrived the last page of each one was entirely W.E. Mall free rides, so she and a coworker carefully cut hundreds of these pages out with razors and split them up for their kids.
I lost count of how many times I've ridden the drop'o'doom... if you hold a coin in one hand and wait for the drop you can make the coin hover weightless above your hand for the whole decent.
It's pretty cool.

       Not that I'm assuming this uses an actual car, but...   

       A front engine car will tend to fall in roughly the right orientation for this to work. The weight at the nose causes it to punch through the air more readily than the tail, and the shape of the car will favor a slightly angled fall. (wind pressure against the roof vs the relatively flat underside).   

       So it's just down to actually landing on the ramp.
MechE, Jan 30 2012

       ^Given that you really really would need small reaction jets to line the car up properly anyways, I think a mid/rear-engined vehicle would serve just as well.   

       Or do it from the top of a cliff to the ramp at the bottom: cliff-diving instead of sky-diving.
FlyingToaster, Jan 30 2012

       // with a real car, carrying real passengers, you only get one try. //   

       To be pedantic (and why not ?) you only get one try per car; you should still have the aircraft and most, if not all, of the ramp.   

       // better yet a caravan or similar //   

       If nothing else, you will at least attract the undivided attention of Jezza Clarkson.   

       // He didn't warm me he was doing this and it scared the bejeezus out of me. //   

       It may have scared the bejeezus out of him, too, if it was an unintentional event ...   

       // So it's just down to actually landing on the ramp //   

       Well, there you are. It's easy. What are you waiting for ?
8th of 7, Jan 30 2012

       I like the cliff version. Could be installed on Beachy Head or some other tourist spot, so punters could drive their car over the edge of the cliff and end up on the beach.
pocmloc, Jan 30 2012

       ... or indeed, "Oh my God, we're all going to die...."
8th of 7, Jan 30 2012

       Would it be easier to build a really big ramp, and hit it at a precise angle and position, or just make a 100x100 foot soft landing spot out of lots and lots of foam?
DIYMatt, Jan 30 2012

       // make a 100x100 foot soft landing spot out of lots and lots of foam//   

       In the case of ramp, car will be able to continue the journey horizontally, without losing much energy as if nothing happened. Humans can survive 5 g without passing out, but they will surely notice it. However, if the ramp is designed for something like 2g or 1 g, it would be a very smooth ride and passengers in the cars may not even notice it.
VJW, Jan 31 2012

       Keep a watch for the Chevy Sonic commercial coming up during the Superbowl.
RayfordSteele, Jan 31 2012


back: main index

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