Tags for this video have been changed from 'parachute, nyc, new york' to 'parachute, nyc, new york, base jumping' - edited by kulpims

Thank you!!

In reply to this comment by kulpims:
*promote

*dupeof=http://videosift.com/video/BASE-Jump-From-Hotel-Elevator

This video has been nominated as a duplicate of this video by kulpims. If this nomination is seconded with *isdupe, the video will be killed and its votes transferred to the original.

>> ^GenjiKilpatrick:

...isn't that the safer way to base jump?
Nothing worse then slamming into the adjacent building/structure before your chute fully deploys.


I'd guess the issue with this method is needing to make sure you jump far enough out that you don't fall through your own chute?

...isn't that the safer way to base jump?

Nothing worse then slamming into the adjacent building/structure before your chute fully deploys.

>> ^maestro156:

So maths ...
according to this website: http://www.csgnetwork.com/stopdistinfo.html, a vehicle slows at roughly 15 feet per second per second, which means in the 0.2 seconds that it takes the bike rider to discover that the truck is braking, the speed of the 90km/h truck would have reduced to about 86-87km/h
which means while the bike will travel 5m in those 0.2 seconds, the truck will travel about 4.8m, putting him 20cm closer to the truck.
Once again, too close for my comfort, but I don't think I'd call it stupid. Just risky, like base jumping and wingsuits.


Adding to the maths frivolities there are some factors that need to be considered....

1) It is a 5 axle truck (they usually have 18 wheels)
2) We don't know if the truck is loaded or not
3) The friction coefficient of bicycle tyres is about 0.75
4) The friction coefficient of truck tyres is about 0.8

If the truck is fully loaded the stopping distance is going to be very far - probably well farther than the bicycle.
If the truck is empty the stopping distance will be a lot less than the bicycle (18 wheels at a higher friction coefficient = stopping on a figurative dime).
So unless we know more information, the calculations are guess work with a very wide margin of error.

I guess it's relative. If you're worried about damaging your bike/car, keep your distance for sure. If you're worried about your life, get as close as you can. If that truck slams on its brakes and you're right next to it, you'll hit the back with a non-lethal force and stick there for as long as the brakes are slammed on.
If I had to choose between this braking scenario on a bike, or some accident while base jumping, I'd choose the bike for sure. Although the chances of a trucker needing to slam on the brakes are probably more remote than having an accident in base jumping.

Of course, as messenger said, I'd be much more worried about debris and potholes...

>> ^CaptainPlanet:

as maestro has astutely pointed out, you've errantly assumed this truck can full stop in zero time. Hurp de durp de durpidy pthhhhhhhhhhh
>> ^Jinx:
>> ^maestro156:
Seems likely to me that he'd be able to brake faster than the truck could break, and if the truck started pulling too far away leaving him exposed, he could coast on the shoulder till he can safely stop.
I'm not saying I would do this, but it doesn't seem all that dangerous. I guess the one thing to worry about would be road debris, since he can't see it coming.

I dont think its about who can stop the fastest, its about how fast you can start stopping.
He's about half a metre away from the back of that truck. He's doing 90kph. Human reaction time is about .2 of a second. Lets do the maths.
90,000m/3600s = 25m/s
25m/s 0.2s = 5m
He's going to travel 5 metres before he even starts slowing down. If that truck has to brake hard he will go into the back of it. Granted, his speed relative to the truck won't be very high but it would prolly be enough to send him arse over tit. at close to 90kph. and he aint exactly in leathers.
I'm not even sure he could stop faster than the truck. Sure, the truck is heavier, but it has 4 wheels, big thick tyres and a lower centre of gravity. Lets do the maths.
The coefficient of friction between road bike tyres and average russian tarmac is...no I kid.


No I didn't? I just assumed the truck would slow enough that he could go into the back of it. So ok, the truck travels 4.8ms, the bike travels 5m. He's now 30cms from the back of the truck, and only now is he gonna start braking. Assuming they decelerate about the same, and I'm not even sure you can stop faster than a truck on a bike, there is still a 3m/s difference in speed with 30cms of room between them. Like I said before, he won't be going very vast relative to the truck when he collides, but his wheels are still going to be spinning prty quickly and I'd guess that would be enough to put him on the pavement...or you know, the risk is large enough that I wouldn't want to try it.


And this is ignoring all the myriad other risks from travelling at 90kph blind. Maybe his attention is on somebody in a car with a video camera in the lane next to him, and suddenly his reaction to the truck braking is delayed...maybe a pothole appears under the truck. Or a puddle. I'd rather base jump than do that.

God, thank you. Jinx's crappy math was really peeving me. you are an asset to the sift

>> ^maestro156:

So maths ...
according to this website: http://www.csgnetwork.com/stopdistinfo.html, a vehicle slows at roughly 15 feet per second per second, which means in the 0.2 seconds that it takes the bike rider to discover that the truck is braking, the speed of the 90km/h truck would have reduced to about 86-87km/h
which means while the bike will travel 5m in those 0.2 seconds, the truck will travel about 4.8m, putting him 20cm closer to the truck.
Once again, too close for my comfort, but I don't think I'd call it stupid. Just risky, like base jumping and wingsuits.

So maths ...

according to this website: http://www.csgnetwork.com/stopdistinfo.html, a vehicle slows at roughly 15 feet per second per second, which means in the 0.2 seconds that it takes the bike rider to discover that the truck is braking, the speed of the 90km/h truck would have reduced to about 86-87km/h

which means while the bike will travel 5m in those 0.2 seconds, the truck will travel about 4.8m, putting him 20cm closer to the truck.

Once again, too close for my comfort, but I don't think I'd call it stupid. Just risky, like base jumping and wingsuits.

10 more comments have been lost in the ether at this killed duplicate.

This video has been declared a duplicate by the original submitter; transferring votes to the original video and killing this dupe - dupeof declared by eric3579.

*dupeof=http://videosift.com/video/Indoor-Base-Jumping-In-a-basilika