Whats the fallrate of a pumpkin?

[bch7773 0]

We are planning on taking a pumpkin up in freefall this weekend, and having a giant pumpkin spaceball jump... but everybody at my DZ has a different opinion of how fast a pumpkin would fall at terminal. Whats your guess?

Its a pretty good size pumpkin, bigger then a persons head. It hasn't been cut open or anything, and the only thing on it is a duct tape handle.

Has anyone been in freefall with a pumpkin and can tell me the speed it fell?

and yes, we are gonna spot way out in the middle of nowhere, and tell people on the ground when we are doing it, etc.

MB 3528, RB 1182

[quade 4]

Lift = (1/2 rho V^2) * area * Cl
See http://www.grc.nasa.gov/WWW/K-12/airplane/foil2.html

My "guess" is that you could do some experiments with the "ball" shaped airfoil and this would come fairly close to your pumpkin, but be aware that it won't be exact and that your pumpkin might go unstable and begin to not fall straight down (track).

When lift (or drag in this case) = weight the pumpkin will be at terminal velocity.

Because of scaling issues, a smaller pumpkin will fall slower than a larger pumkin.

quade -
The World's Most Boring Skydiver

[Maxx 1]

Hi,

I saw a video with a pumpkin, where the pumpkin went stable at first but then began spinning faster and faster. The inside of the pumpkin began to press against the paring and after 10 or 15 seconds the pumpkin exploded very hard and someone flying above the pumpkin got a nice topping..

The reason for this was that the pumpkin was slightly oval shaped and therefore asymmetric.. Be sure to get a good symmetric pumpkin!

But the people around them were flying on their belly, IIRC.

Feet up!
Max

[darkwing 5]

It depends on too many variables in subtle ways to give a useful answer. I jumped a watermelon in 1973 and it was very fast. I held it all the way to opening, otherwise we never would have gotten close to it. A photo is on my page linked below. Look for watermelon in the photo album.

I think pumpkins are less dense than watermelons, so I'm thinking that a pumpkin the size of a persons head might have an acceptable fall rate, but still, it is all educated guesswork until you do it.

-- Jeff
My Skydiving History

[2cmyzx 0]

We dropped a couple good size pumpkin's this year and they were fairly large. I was on the ground and they left holding the pumpkin and when at terminal released it. One of the expert freefly instructor went heads down and just caught up to it at breakoff. The best was we cut the top out, hollowed out enough for 2 smoke canisters, cut small hole in side for the smoke canister string, insert canister and tape top back on with duct tape. It was very visable from the ground. My guess is that it would have to be a very small pumpkin to be able to belly fly with.

[JohnMitchell 16]

Back in the eighties we jumped with a pumpkin about like what you're describing. We belly flew around, passing it off in free fall, no trouble. At breakoff, I hucked it and watched it fall beneath us, maybe 15-20 mph faster. It did start spiraling away. Might be hard to grab one moving like that, but also fun to try.

Make sure you spot over something cheap.

[TomAiello 26]

On towers where an average jumper takes 10, I've seen pumpkins impact around 18-20. So I voted "slower than belly."

-- Tom Aiello

Tom@SnakeRiverBASE.com
SnakeRiverBASE.com

[kallend 2,147]

Drag coefficient is around 0.5 for a pumpkin.

The fall rate depends on it's size and weight. Provide those and the fall rate can be calculated.

...

The only sure way to survive a canopy collision is not to have one.

[AndyMan 7]

Pumkins are largely empty, thus less dense than people.

Fall rate would be slower than belly.

_Am

__

You put the fun in "funnel" - craichead.

[freakbrother 0]

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Pumkins are largely empty, thus less dense than people.

Fall rate would be slower than belly.

_Am

Not hard, most people are pretty dense. You can tell that from election results

.
.
www.freak-brother.com

[mr2mk1g 10]

So why not cut a small hole, fill it up with water, then plug the hole.

Do the sums as Kallend suggests and you should be able to work out how much water to use in order to get it to fall at the same speed as you... at least with enough accuracy that it wont be wildly off and thus outside your range of control.

[upndownshop 0]

Quote

We are planning on taking a pumpkin up in freefall this weekend, and having a giant pumpkin spaceball jump... but everybody at my DZ has a different opinion of how fast a pumpkin would fall at terminal. Whats your guess?

Its a pretty good size pumpkin, bigger then a persons head. It hasn't been cut open or anything, and the only thing on it is a duct tape handle.

Has anyone been in freefall with a pumpkin and can tell me the speed it fell?

and yes, we are gonna spot way out in the middle of nowhere, and tell people on the ground when we are doing it, etc.

I can't tell you the speed at which it will fall, but I can tell you that it can go through a roof of a building and that was from only 800'. It went through the roof of the bathrooms at Mike Mullins place, while someone was in there. No injuries except to the roof.

Be very very careful.

Have fun

[BlindBrick 0]

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[but I can tell you that it can go through a roof of a building and that was from only 800'. It went through the roof of the bathrooms at Mike Mullins place, while someone was in there. No injuries except to the roof.

What a great place to be if you're going to get the shit scared out of you!
-Blind

"If you end up in an alligator's jaws, naked, you probably did something to deserve it."

[BillyVance 35]

I can't tell you the speed at which it will fall, but I can tell you that it can go through a roof of a building and that was from only 800'. It went through the roof of the bathrooms at Mike Mullins place, while someone was in there. No injuries except to the roof.

Be very very careful.

Have fun

[YahooLV 0]

Is it gonna arch? Will you be using gripers?

My guess.....bat outta hell and pickin up speed!

http://www.curtisglennphotography.com

[JohnRich 4]

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Pumkins are largely empty, thus less dense than people.
Fall rate would be slower than belly.

My practical experience says otherwise - pumpkins are *faster* than belly-flyers - I would say about 130-140 mph for a basketball-sized pumpkin.

I haven't done one in a while, due to real estate development around our once remote DZ. But for the last one, we passed a small pumpkin around a four-way RW formation, and when it got to the last guy, he released it and we all chased it. It accelerated, and dove in a corkscrew spiral due to the asymmetric shape. Which made for a heck of a lot of fun with a bunch of guys chasing it...

[winsor 236]

We used to make "Sunkist" dives, which were great fun. A large, spherical navel orange was found to have a fall rate that was no problem with which to stay relative in freefall (bellyflying). Just toss it out the door and chase.

If you have one that is asymmetrical, be prepared for it to begin spinning. It will then require quite a serious track to stay anywhere close to it.

Given a particular density, fall rate will tend to increase with size. IIRC, to keep fall rate constant, the weight of the object should vary with its area, rather than volume. A 10 cm ball that weighs 100 gm should fall at the same rate as a 20 cm ball that weighs 400 gm. A 20 cm ball with the same density as the 10 cm ball will weigh 800 gm and fall 1.41 times as fast.

Playing with the numbers, given a 12 cm orange falling at 120 mph, a 33.3 cm orange would be doing 200 mph at terminal. If a pumpkin has density similar to an orange, you would have to stand on your head to keep up with one 1 foot in diameter.


Blue skies,

Winsor

[johnny1488 1]

This was my second year of doing pumpkin drops from under canopy. We droped them anywhere from 500 to 1000 feet. I think that would be enough for terminal. They were going 100+ easy. Thats as close as I can estimate, but be carefull. They boogie!

Johnny
--"This ain't no book club, we're all gonna die!"
Mike Rome

[mjosparky 4]

Years ago, during a Halloween meet, I dropped a pumpkin during a "pumpkin pass" dive. It was about 12 to 14 inches in diameter. It took off like I was standing still. I dropped it at around 5,000 feet and it hit the ground about the time I got open, 2,500, 2,800 or so.

No idea how fast it went but it had to be 180 +.

Sparky

My idea of a fair fight is clubbing baby seals

[Treejumps 0]

I have docked on a pumpkin head down. It is obviously very size dependent, but I would expect it to be at least a fast belly speed.

[JohnRich 4]

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We used to make "Sunkist" dives, which were great fun. A large, spherical navel orange...

A long time ago we used to do occasional "salad" dives, whereby everyone would arrive at the DZ with some fruit or vegetable purchased from the grocery store. We would make a round formation while holding onto our veggies, and then on cue, everyone would hold their pick out in front of them and release it. It was a hoot to see which ones went up, which went down, and which stayed with you.

I miss those days.

[bch7773 0]

Well everyone, the moment you have been waiting for.... the answer to the question is:

Faster then a sitfly!!!


We jumped the pumpkin today, exit went great, and when i was holding onto it we were doing about normal belly speeds, but then i handed it off to another jumper and he dropped it. It fell like a rock, and he went headdown after it. The camera guy and I both went into spikes and could barely keep up. The jumper in headdown fell about the same speed as it, and almost managed to grab it.

It fell pretty stable, not a lot of spinning, but it slid around the sky quite a bit. It was a lot of fun.

so anyways, the 22% of you who guessed "faster then sitfly speed" were right.

MB 3528, RB 1182

[colossus 0]

Told yah!

Before Halloween we were jumping pumpkins.
And as one of my fellow jumpers said... "If you thought a pumpkin was fun, yah gotta see a watermellon".
Ahh btw. If you REALLY want to see something cool, check out the impact crater.

• Quote

[Unstable 9]

It was absolutly beautiful, Bch!! I watched it from the ground, and it was creepy to see the pumpkin hit the ground about a quarter-mile away, feel the shockwave in my feet, then a second or two later hear the "WHOMP" of a pumpkin smashing into idy bitty pieces. I want to go and try to find the impact crater sometime....

=========Shaun ==========

[JohnMitchell 16]

For more pumpkin fun, put an old junk car in the middle of the DZ and do some pumpkin bombing from the C-182. We used 200 feet AGL and 100 mph. Got a lot of near misses and the next load got a bullseye on the 2nd pass. Of course, we were standing right f#$king behind the van when it hit. Awesome.