Slinging.org Forum - Supersonic sling projectile?

lobohunter Interfector Viris Spurii Offline where be a rock and a string there be a sling Posts: 1982 Cottage Grove or Gender:	Re: Supersonic sling projectile? Reply #15 - Jan 7^th, 2008 at 12:57pm hmmm the un answered question can a human hurl a projectile at mach1 +
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DesertPilot

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Re: Supersonic sling projectile?
Reply #16 - Jan 7^th, 2008 at 5:41pm

I ran a bunch of simulations a year or so ago, and the answer seems to be that since a sling is straight -- unlike a whip, which flexes during the snap -- the only way you could pull it off would be with a Really Long Sling: at least 150' long, and perhaps much longer. And even then, you'd have to find some way to deal with air resistance. But this simulation was far from the last word on the subject, since I didn't handle the dynamics of the slinger's body properly, and I only modeled certain types of throws.

If I can ever find a way to improve the simulation and compare it with actual measurements, I may give it another go...

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Re: Supersonic sling projectile?
Reply #17 - Jan 7^th, 2008 at 5:58pm

Let's just make a few "ball-park" calculations Just to see if we're even going to get close. To make it simple we'll ignore the actual weight of the sling and the force that moving it through air at that speed would require, consider only the centrifugal force.

Size and weight assumptions:

A nice long sling length, of 2 metres (78 inches)
Mass of the projectle of 50 grams ( Approx 2 ounces as used by Larry Bray to set the real word record)
Speed of sound approx. 300 metres per second

Centripetal Force F= m x v^2/r

Plug in the numbers into your faithful calculator and the force required just to hold the rotating cords of the sling works out as 2250 N or a shade under 500 pounds

That's the absolute minimum your little slinging pinkies will have to be holding just to get the sling up to speed. All the complications make that figure worse.

Also translate 300 m/s into rotational speed and that sling is rotating at over 1400 rpm assuming a steady circular motion.

Based on the above I think that we can fairly safely say the answer is no. (Now just watch some clever type prove me wrong.)

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DesertPilot

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Re: Supersonic sling projectile?
Reply #18 - Jan 7^th, 2008 at 10:27pm

With a 50m sling rotating at 60 RPM (one rotation per second), the projectile velocity would a hair greater than Mach 1, and the g-forces would be around 180 g's. Even for a 50 gm projectile, this would translate to a quite-managable 9 kg (20 lbs). Unfortunately, if I've done the calculation correctly, the air drag for 1mm paracord would be around 25 lbs, and the slinger would have to generate something like 50 hp to swing the thin at Mach 1. I'm sure there are some folks on this list who could pull this off, but alas, I am not one of them...

Of course, this is all back-of-the-envelope stuff, done after a glass or two of wine, so it's quite possible I'm off by a few decimal places...

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CanDo

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Re: Supersonic sling projectile?
Reply #19 - Jan 7^th, 2008 at 10:30pm

DesertPilot wrote on Jan 7^th, 2008 at 10:27pm:

With a 50m sling rotating at 60 RPM (one rotation per second), the projectile velocity would a hair greater than Mach 1, and the g-forces would be around 180 g's. Even for a 50 gm projectile, this would translate to a quite-managable 9 kg (20 lbs). Unfortunately, if I've done the calculation correctly, the air drag for 1mm paracord would be around 25 lbs, and the slinger would have to generate something like 50 hp to swing the thin at Mach 1. I'm sure there are some folks on this list who could pull this off, but alas, I am not one of them...

Of course, this is all back-of-the-envelope stuff, done after a glass or two of wine, so it's quite possible I'm off by a few decimal places...

What is the airspeed velocity of an unladen swallow? Grin

I think that it's pretty safe to say that there are no sling stones passing the sound barrier. Maybe a projectile smaller than a BB placed at the end of a whip...? Maybe?

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Curious Aardvark

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Re: Supersonic sling projectile?
Reply #20 - Jan 8^th, 2008 at 10:26am

[quote]a shade under 500 pounds
[/quote]

Well the answer is obvious - use a forearm brace to anchor the cord and teach Mariusz Pudzianowski to sling :-)
[url]http://en.wikipedia.org/wiki/Mariusz_Pudzianowski[/url]

It's doable.
And if he doesn't have the bodyweight to anchor the cord then go ask dominic filiou :-)

At over 6'5" (1.96 cm) and weighing in excess of 440 lbs (31 stone)[1], he is one of the biggest strongmen in the world. His biceps measure 24" and his waist measures 48".

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Aussie Past Moderator Offline Joined Nov. 1, 2006 Luke 14:14 Posts: 3265 Melbourne, Australia Gender:	Re: Supersonic sling projectile? Reply #21 - Jan 8^th, 2008 at 4:14pm Can either of them whiz their arms around at the equivalent of 1400 RPM though?
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Re: Supersonic sling projectile?
Reply #22 - Jan 8^th, 2008 at 4:35pm

If all one is measuring, as stated earlier, is 'average velocity' as displayed by an artificially circular sling cast, I vote Aussieslinger build a kevlar 'Aussiepouch' attached to sturdy kevlar sling cords which are, in turn, attached to a suitable scale propped up at a suitable angle. Then fire various small caliber guns point blank at the hanging pocket such that the round is caught tangential to the arc of travel. Video the readout.

Shocked

I wonder what the results would actually be? Perhaps only NWmanitou knows for sure?

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Ethan Funditor Offline so much depends upon a red wheelbarrow... Posts: 858 On the edge of a lake... Gender:	Re: Supersonic sling projectile? Reply #23 - Jan 8^th, 2008 at 4:38pm 1400 rpm shoudln't be hard for a car engine! Anyone want to hook up a sling to one of those?
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Aussie Past Moderator Offline Joined Nov. 1, 2006 Luke 14:14 Posts: 3265 Melbourne, Australia Gender:	Re: Supersonic sling projectile? Reply #24 - Jan 9^th, 2008 at 4:17am Actually supersonic pojectile speeds are easy. Just get a gun.
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LKH9 Funditor Offline Posts: 824 Malaysia Gender:	Re: Supersonic sling projectile? Reply #25 - Jan 9^th, 2008 at 8:44am I'm more interested in the shooting of stones using a whip. I did think of something like that before, but it's really possible. =O
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wanderer

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Re: Supersonic sling projectile?
Reply #26 - Jan 9^th, 2008 at 9:01am

DesertPilot wrote on Jan 7^th, 2008 at 10:27pm:

With a 50m sling rotating at 60 RPM (one rotation per second), the projectile velocity would a hair greater than Mach 1, and the g-forces would be around 180 g's. Even for a 50 gm projectile, this would translate to a quite-managable 9 kg (20 lbs). Unfortunately, if I've done the calculation correctly, the air drag for 1mm paracord would be around 25 lbs, and the slinger would have to generate something like 50 hp to swing the thin at Mach 1. I'm sure there are some folks on this list who could pull this off, but alas, I am not one of them...

Of course, this is all back-of-the-envelope stuff, done after a glass or two of wine, so it's quite possible I'm off by a few decimal places...

.. and you are going to have to have very long arms to keep it moving Wink

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Curious Aardvark Forum Moderation Offline Taller than the average Dwarf Posts: 13965 Midlands England Gender:	Re: Supersonic sling projectile? Reply #27 - Jan 9^th, 2008 at 6:42pm anybody know of a working windmill in a hurricane zone ;-)
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Africa_Slinger Senior Member Offline I love Slinging.org! Posts: 259 Johannesburg, South Africa Gender:	Re: Supersonic sling projectile? Reply #28 - Jan 10^th, 2008 at 2:20am Give the sling projectile to your local fighter pilot and tell him to take it supersonic, there easy, supersonic sling projectile.
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Curious Aardvark

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Re: Supersonic sling projectile?
Reply #29 - Jan 11^th, 2008 at 6:48am

Ah but does it count if it's inside an aeroplane ?
If so any one of us could take a small sling (this is the year of the short sling after all) on their next plane trip and sling a paper ball in the toilet. That missile might then be deemed to have broken the sound barrier.

I'm guessing it doesn't count :-)

How about attaching a sling to a wind generator the big ones certainly have the speed and power to do the job and if a slinger were o strap thmselves to a harness at the tip of ablade they might get up to speed :-)

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