# Thread: I need this to cool off!

1. ## I need this to cool off!

2. that looks like a lot of fun

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Everything looks to be in accordance with the rules of physics.

Divide the time from start position to lowest position point into 5 time segments. Call them seconds - for convenience.

The seconds from start height to lowest point is about equal as those from lowest point to highest point when air borne.

The distance travelled after going airborne also seems consistent with the velocity attained after 3 seconds on the initial downward run which should be about the velocity after the 2 seconds spent on the upward run before going air borne. This not his speed but his velocity in the direction of the pool I'm talking.

Now, we have one of those pools in the back ward for the kids and I worry that it is just not enough water to stop someone at that speed - also without topping the pool over. But if I had the time I could do a conservation of mommentum calculation regarding impulse force to work out what mass of water at what speed would carry forward the preservation of kinetic energy. Why did he not hit and then bounce back out the other side of the pool?

It looks like they have a dummy at the end of the ramp on the floor that they used to get the distance right. The weight of the dummy would not matter except for simulating the friction of the body in a suite on the slide material.

4. Originally Posted by Marc O'Brien
Everything looks to be in accordance with the rules of physics.

Divide the time from start position to lowest position point into 5 time segments. Call them seconds - for convenience.

The seconds from start height to lowest point is about equal as those from lowest point to highest point when air borne.

The distance travelled after going airborne also seems consistent with the velocity attained after 3 seconds on the initial downward run which should be about the velocity after the 2 seconds spent on the upward run before going air borne. This not his speed but his velocity in the direction of the pool I'm talking.

Now, we have one of those pools in the back ward for the kids and I worry that it is just not enough water to stop someone at that speed - also without topping the pool over. But if I had the time I could do a conservation of mommentum calculation regarding impulse force to work out what mass of water at what speed would carry forward the preservation of kinetic energy. Why did he not hit and then bounce back out the other side of the pool?

It looks like they have a dummy at the end of the ramp on the floor that they used to get the distance right. The weight of the dummy would not matter except for simulating the friction of the body in a suite on the slide material.
Hi Marc
you forgot to add in the consent of gravity

how you doing

5. Marc, are you saying that this is you flying through the air in this video?

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Seriously - the whole web seems to think this is a fake. Only those who claim to know a little of physics suggest it could be real.

I think it could be done - I just don't like the BS about magnetic slipperyness improvers - but I can't say its not true just because it sounds unecessary to me.

So I did some quick calcs assuming the vertical distance from the start point on the slide to the trough is about 10m.

The two things that don't make sense to me still are how gentle the landing is. However...

The height he falls from into the pool is at least 5 meters? If the pool could have been located about 5m higher then vertically it would have been a zero gravity approach.

His horizontal velocity would be about COS 30° x (6 x 9.81 x 2)^0.5 = 9.4m/s and his vertical about (5 x 9.81 x 2)^0.5 = 9.9m.

The vector sum of velocities would be about (9.9˛ + 9.4˛)^0.5 = 13.6m/s which is equal to falling into the pool at an angle from about 10m high. Scary but not out of this world.

If he hits the pool right and uses the full width of water for slowing down and shapes his body for max resistance then I think it can be done with just minor bruises.

7. but I saw Wiley Coty do it on when try to get the Roadrunner

And he a genius

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Originally Posted by fcs
but I saw Wiley Coty do it on when try to get the Roadrunner

And he a genius
Why yes, of course, and I can bear testament to that too. Truely a genius as genius as genius gets

9. Originally Posted by Marc O'Brien
Why yes, of course, and I can bear testament to that too. Truely a genius as genius as genius gets
But it never works he must be PE

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Originally Posted by fcs
But it never works he must be PE
Oh, he'll get is right someday - physics is 99.9% failure and 0.1% progress per, well, generation maybe

11. I don't know if I would trust the aim of my own body on the calculations, because of the possibility that some variable would change or simply be wholly different from my estimates. That pool is sitting on a wooden platform that could shatter a pelvis, or drive a femur up into your chest.

12. Watching that body in slow motion fly through the air looks real to me. I actually think some jackass did this amazing stunt.

13. looks real to me,that is one crazy dude...

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