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Posted: 6/6/2008 5:19:57 AM EST
[Last Edit: 6/6/2008 5:28:38 AM EST by shrikefan]
Meat and potatoes from the threadjack.


Originally Posted By shrikefan:
Everybody is talking about the laws of physics. I have a question: I launch a projectile at an object, the bulk of that object winds up about 15 ft closer in a straight line in the direction from which the projectile came after the projectile passed through it. How is this possible? Did this violate a law of physics or something else?

Sorry for the semi-jack.

ETA - the bulk of




Originally Posted By Keith_J:

Originally Posted By shrikefan:
Everybody is talking about the laws of physics. I have a question: I launch a projectile at an object, the bulk of that object winds up about 15 ft closer in a straight line in the direction from which the projectile came after the projectile passed through it. How is this possible? Did this violate a law of physics or something else?

Sorry for the semi-jack.

ETA - the bulk of
\


Originally Posted By Forest:

Originally Posted By shrikefan:

Originally Posted By shrikefan:
Everybody is talking about the laws of physics. I have a question: I launch a projectile at an object, the bulk of that object winds up about 15 ft closer in a straight line in the direction from which the projectile came after the projectile passed through it. How is this possible? Did this violate a law of physics or something else?

Sorry for the semi-jack.

ETA - the bulk of


Can anyboby help a brother out? I guess all the smart people are logged out right now.



Originally Posted By shrikefan:

Originally Posted By Forest:

Originally Posted By shrikefan:

Originally Posted By shrikefan:
Everybody is talking about the laws of physics. I have a question: I launch a projectile at an object, the bulk of that object winds up about 15 ft closer in a straight line in the direction from which the projectile came after the projectile passed through it. How is this possible? Did this violate a law of physics or something else?

Sorry for the semi-jack.

ETA - the bulk of


Can anyboby help a brother out? I guess all the smart people are logged out right now.



Originally Posted By PaDanby:

Originally Posted By shrikefan:

Originally Posted By shrikefan:
Everybody is talking about the laws of physics. I have a question: I launch a projectile at an object, the bulk of that object winds up about 15 ft closer in a straight line in the direction from which the projectile came after the projectile passed through it. How is this possible? Did this violate a law of physics or something else?

Sorry for the semi-jack.

ETA - the bulk of


Can anyboby help a brother out? I guess all the smart people are logged out right now.


It's marginally possible. It's a conservation of momentum and conservation of energy thing. You shoot a projectile in to the gel (am I correct in that you are talking gel, or fruit or similar objects). As it expands and blows a lot of the object out the back side some of the stuff is going to come flying back to the front.

Energy at time 1 = Blob at 0 velocity (0 kinetic energy) and projectile at x velocity (xxx ft pounds of kinetic energy) Total Kinetic Energy = xxx, Momentum is similar, blob has 0 and bullet has a bunch of both linear and rotational .

Energy at time 2 projectile has entered blob, that blob and bullet now contain all the energy and momentum. the blob is causing the bullet to slow down thats linear momentum and slowing the spinning, that converts some of the kinetic energy to heat energy and imparting KE to various pieces of the blob.

At time 3 there are pieces of blob and bullet flying all over the place. The kinetic energy in all the pieces adds up to the KE at time 1 minus any energy converted to heat, and the total linear momentum of all the pieces (vector math here) is equal to the total linear momentum at time 1, and the total rotational momentum of all the pieces at time one.

So yes in all that energy conversion and momentum conservation a bunch can easily come back at you. (There are additional friction losses, and gravity also has an effect, since this isn't in a gravity free and atmoshere free environment, but those can be accounted for with a lot more complicated equations.)




Originally Posted By shrikefan:

Originally Posted By AR4U:
i177.photobucket.com/albums/w233/venemanuarizonaedu/bulletapple.jpg

note back spatter


AR4U,

With a few modifications the basis of this pic is a great representation of what I was talking about.

The mods would be:

The target standing on it's own,
Leave the spatter (back and front) around the original target site,
Move the rest of the target back about 15ft, in this case to the right where the bullet came from,
The original target was a couple oz vermin.

Thanks all for your intelligent input. Any conversions to laymans terms is greatly appreciated as a lot of the science stuff is way beyond my pay grade.




Originally Posted By shrikefan:

Originally Posted By Keith_J:
Well, to make the target move TOWARD the shooter? The target is a sphere that traps the bullet, starting the sphere rotating towards the shooter.

There you go!


The bullet went all the way through and was not trapped.



Originally Posted By shrikefan:
Originally Posted By Tolip:
Originally Posted By shrikefan:
Originally Posted By Keith_J:
Well, to make the target move TOWARD the shooter? The target is a sphere that traps the bullet, starting the sphere rotating towards the shooter.

There you go!


The bullet went all the way through and was not trapped.


Surely it deposited some energy on the way through...


Yes, but what causes that energy to be transfered 180 degrees to the direction of input? Logic says it would have traveled in a similar direction as the energy transferer.
Link Posted: 6/6/2008 5:21:48 AM EST
Are you discovering alternating electrical current?
Link Posted: 6/6/2008 5:26:31 AM EST
[Last Edit: 6/6/2008 5:27:37 AM EST by Tolip]
unpossible

Link Posted: 6/6/2008 5:29:46 AM EST
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.

Link Posted: 6/6/2008 5:30:12 AM EST
VBC and Tolip,

Go back and read my edits.

Thanks,

SF
Link Posted: 6/6/2008 5:31:09 AM EST
It ran toward the shooter's direction before it died.
Link Posted: 6/6/2008 5:36:05 AM EST

Originally Posted By shrikefan:
VBC and Tolip,

Go back and read my edits.

Thanks,

SF


Linear and angular momentum can be interconverted.

Your quotes are messed up.


Originally Posted By shrikefan:

Originally Posted By Tolip:

Originally Posted By shrikefan:

Originally Posted By Keith_J:
Well, to make the target move TOWARD the shooter? The target is a sphere that traps the bullet, starting the sphere rotating towards the shooter.

There you go!


The bullet went all the way through and was not trapped.


Surely it deposited some energy on the way through...


Yes, but what causes that energy to be transfered 180 degrees to the direction of input? Logic says it would have traveled in a similar direction as the energy transferer.


Link Posted: 6/6/2008 5:36:30 AM EST

Originally Posted By VBC:
It ran toward the shooter's direction before it died.


There is no way it could have run - it looked like it was turned inside out.
Link Posted: 6/6/2008 5:37:39 AM EST
[Last Edit: 6/6/2008 6:23:05 AM EST by PAEBR332]
Nobel prize winning physicist Richard Feynman Luis W. Alvarezexplained the physics behind this phenomenon decades ago. He did so in demonstrating why Kennedy's head snapped to the rear, the direction from which the fatal shot was fired.

ETA: Correct Nobel Laureate.
Link Posted: 6/6/2008 5:38:48 AM EST

Originally Posted By Keith_J:
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.



Is he also a JFK conspiracy theorist?

"back and to the left
back and to the left
back and to the left
back and to the left
back and to the left
back and to the left..."
Link Posted: 6/6/2008 5:39:20 AM EST

Originally Posted By Tolip:

Originally Posted By shrikefan:
VBC and Tolip,

Go back and read my edits.

Thanks,

SF


Linear and angular momentum can be interconverted.

Your quotes are messed up.


Originally Posted By shrikefan:

Originally Posted By Tolip:

Originally Posted By shrikefan:

Originally Posted By Keith_J:
Well, to make the target move TOWARD the shooter? The target is a sphere that traps the bullet, starting the sphere rotating towards the shooter.

There you go!


The bullet went all the way through and was not trapped.


Surely it deposited some energy on the way through...


Yes, but what causes that energy to be transfered 180 degrees to the direction of input? Logic says it would have traveled in a similar direction as the energy transferer.




PLease put that in layman's terms. Thank you.


How? I did a straight cut and paste. I did omit some that did not really contribute to the OP.
Link Posted: 6/6/2008 5:39:49 AM EST

Originally Posted By Keith_J:
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.



Bernouli effect? Isn't that where a spinning body can generate lift on one side?
Link Posted: 6/6/2008 5:40:58 AM EST

Originally Posted By PAEBR332:
Nobel prize winning physicist Richard Feynman explained the physics behind this phenomenon decades ago. He did so in demonstrating why Kennedy's head snapped to the rear, the direction from which the fatal shot was fired.


Any links?

Thanks.
Link Posted: 6/6/2008 5:42:38 AM EST

Originally Posted By Tolip:

Originally Posted By Keith_J:
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.



Is he also a JFK conspiracy theorist?

"back and to the left
back and to the left
back and to the left
back and to the left
back and to the left
back and to the left..."


No. Just an observation of the facts on my part. There is too much speculation on the JFK issue.
Link Posted: 6/6/2008 5:45:39 AM EST
[Last Edit: 6/6/2008 5:46:07 AM EST by shrikefan]

Originally Posted By Torf:

Originally Posted By Keith_J:
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.



Bernouli effect? Isn't that where a spinning body can generate lift on one side?


Interesting, but wouldn't that give a 90 degree deviation (at most) from the original direction?

I'm talking 180 degrees +/- a couple degrees.
Link Posted: 6/6/2008 5:46:51 AM EST
Where's Michael Courtney.
Link Posted: 6/6/2008 5:47:53 AM EST
lol
Link Posted: 6/6/2008 5:48:01 AM EST

Originally Posted By VBC:
Where's Michael Courtney.


Please explain.
Link Posted: 6/6/2008 5:52:53 AM EST

Originally Posted By shrikefan:

Originally Posted By VBC:
Where's Michael Courtney.


Please explain.


Dr. Courtney is a physicist and a member here.
Link Posted: 6/6/2008 5:54:57 AM EST
[Last Edit: 6/6/2008 5:55:53 AM EST by GonzoAR15-1]
Entry wound: Small.

Exterior: Flesh (elsastic).

Internal dynamics: Viscous combination of fluids and gases (lungs).

Exit Wound: Large

Theory: Bullet enters and dumps massive amounts of entry liquifying and pressurizing guts of critter, most especially full lungs full of air. It immediately exists with a larger wound than the entry. The pressurized innards seek equilibrium by taking the path of least resistance, out the exist hole. Like a "water rocket" the mass of flesh and air and liquid that blows out of the exit wound acts as a source of thrust and flings the critter in the opposite direction.

Link Posted: 6/6/2008 5:55:02 AM EST

Originally Posted By PAEBR332:

Originally Posted By shrikefan:

Originally Posted By VBC:
Where's Michael Courtney.


Please explain.


Dr. Courtney is a physicist and a member here.


I wait with bad baited breath.
Link Posted: 6/6/2008 5:56:33 AM EST

Originally Posted By GonzoAR15-1:
Entry wound: Small.

Exterior: Flesh (elsastic).

Internal dynamics: Viscous combination of fluids and gases (lungs).

Exit Wound: Large

Theory: Bullet enters and dumps massive amounts of entry liquifying and pressurizing guts of critter, most especially full lungs full of air. It immediately exists with a larger wound than the entry. The pressurized innards seek equilibrium by taking the path of least resistance, out the exist hole. Like a "water rocket" the mass of flesh and air and liquid that blows out of the exit wound acts as a source of thrust and flings the critter in the opposite direction.



Simple kids toy physics?
Link Posted: 6/6/2008 6:08:04 AM EST
[Last Edit: 6/6/2008 6:08:34 AM EST by GonzoAR15-1]

Originally Posted By shrikefan:

Originally Posted By GonzoAR15-1:
Entry wound: Small.

Exterior: Flesh (elsastic).

Internal dynamics: Viscous combination of fluids and gases (lungs).

Exit Wound: Large

Theory: Bullet enters and dumps massive amounts of entry liquifying and pressurizing guts of critter, most especially full lungs full of air. It immediately exists with a larger wound than the entry. The pressurized innards seek equilibrium by taking the path of least resistance, out the exist hole. Like a "water rocket" the mass of flesh and air and liquid that blows out of the exit wound acts as a source of thrust and flings the critter in the opposite direction.



Simple kids toy physics?



Hey, just my theory. Don't post a thread asking for input and then insult people who throw things out.

If you've ever seen the "high speed" videos of the high velocity varment shoots, the ones that kick back toward the shooter always have a jet of entrails exiting the back. My working theory is that if the lungs are full when the bullet hits, the compressibility of the air makes a difference.

Link Posted: 6/6/2008 6:14:00 AM EST
Link Posted: 6/6/2008 6:19:09 AM EST

Originally Posted By GonzoAR15-1:

Originally Posted By shrikefan:

Originally Posted By GonzoAR15-1:
Entry wound: Small.

Exterior: Flesh (elsastic).

Internal dynamics: Viscous combination of fluids and gases (lungs).

Exit Wound: Large

Theory: Bullet enters and dumps massive amounts of entry liquifying and pressurizing guts of critter, most especially full lungs full of air. It immediately exists with a larger wound than the entry. The pressurized innards seek equilibrium by taking the path of least resistance, out the exist hole. Like a "water rocket" the mass of flesh and air and liquid that blows out of the exit wound acts as a source of thrust and flings the critter in the opposite direction.



Simple kids toy physics?



Hey, just my theory. Don't post a thread asking for input and then insult people who throw things out.

If you've ever seen the "high speed" videos of the high velocity varment shoots, the ones that kick back toward the shooter always have a jet of entrails exiting the back. My working theory is that if the lungs are full when the bullet hits, the compressibility of the air makes a difference.



Gonz,

It wasn't meant to be an insult at all. I was just feeling kinda STOOPID that I may have missed out on some of my childhood.

I was originally thinking that maybe the momentum/mass of this critter turning inside out was what caused it to move in the direction it did. There is probably some time/energy science/math type stuff to explain it. I will also need someone with excellent translation skills to help me comprehend it.

Thanks for your input - absolutely no offense intended.
Link Posted: 6/6/2008 6:22:21 AM EST
[Last Edit: 6/6/2008 6:30:45 AM EST by PAEBR332]

Originally Posted By shrikefan:

Originally Posted By PAEBR332:
Nobel prize winning physicist Richard Feynman explained the physics behind this phenomenon decades ago. He did so in demonstrating why Kennedy's head snapped to the rear, the direction from which the fatal shot was fired.


Any links?

Thanks.


Oops. Wrong physicist. Luis W. Alvarez was the Nobel laureate who did this.

I do not know if this is available online anywhere: American Journal of Physics, Vol. 44, No. 9, September 1976 Pages 813 - 827 "A Physicist Examines the Kennedy Assassination Film" Luis W. Alvarez

ETA: Found the PDF online. You have to subscribe to read it: scitation.aip.org/vsearch/servlet/VerityServlet?KEY=AJPIAS&CURRENT=NO&ONLINE=YES&smode=strresults&sort=rel&maxdisp=25&threshold=0&pjournals=AJPIAS&pyears=2001%2C2000%2C1999&possible1=A+Physicist+Examines&possible1zone=article&SMODE=strsearch&OUTLOG=NO&viewabs=AJPIAS&key=DISPLAY&docID=1&page=1&chapter=0

Link Posted: 6/6/2008 6:27:46 AM EST

Originally Posted By AeroE:

Originally Posted By VBC:
It ran toward the shooter's direction before it died.


Involuntary muscle movement caused it jump, or dirt kicked up from the bullet impact shoved the little guy back toward the shooter. A jet of high pressure blood and guts might have contributed.



I'm sure any involuntary muscle movement was caused by the 150 gr slug going through it at 3400 fps. The dirt was approx 3-4 ft behind as I recall. The high pressure jet theory may hold some good merit.

Had I known at the time the act was going to be this intriguing I would have found a way to set up high speed camera's and the like. Hind sight is 20/20.
Link Posted: 6/6/2008 6:29:38 AM EST
[Last Edit: 6/6/2008 6:31:36 AM EST by santanatwo]

Originally Posted By Tolip:

Originally Posted By Keith_J:
He is trying to understand how a small animal, shot with a rifle, ends up closer to the shooter's position.



Is he also a JFK conspiracy theorist?

"back and to the left
back and to the left
back and to the left
back and to the left
back and to the left
back and to the left..."


That is exactly wha tI was thinking,

when JFK was shot his head flew BACK!!!!

obviously because he was shot it the back of the head.

then they tried to prove it on a documentary, bu shooting a human skull (no skin or flesh) and when a chucnk of the skull went flying backwards they said "see that prooves it!"


(ignoring the fact that the rest of the skull vaporized and went flying forward....)

oh yeah, and anybody who has shot shit witha high power rifle knows the exit hole is bigger... but JFK's exit hole was mysteriously tiny, and the "entry wound" int he back of his head was massive...

yeah right...


JFK was shot from the front.... I'm guessing with a silenced 45

Link Posted: 6/6/2008 6:30:42 AM EST
[Last Edit: 6/6/2008 6:31:16 AM EST by VBC]
If there was a dirt backstop, it might have hit that and bounced forward.

Sort of like when shooting cans against a dirt backstop. They'll fly back, hit the dirt, then bounce and roll forward.
Link Posted: 6/6/2008 6:33:16 AM EST
[Last Edit: 6/6/2008 6:58:34 AM EST by rmstrjim]
Isn't it the "jet" of material "shooting" out the exit wound that propels the carcass towards the direction of the shooter?
Link Posted: 6/6/2008 6:47:59 AM EST

Originally Posted By VBC:
If there was a dirt backstop, it might have hit that and bounced forward.

Sort of like when shooting cans against a dirt backstop. They'll fly back, hit the dirt, then bounce and roll forward.


There was no evidence that the carcass bounced off of anything behind it. No entrail smears, impressions in the ground, etc..
Link Posted: 6/6/2008 6:54:00 AM EST
Link Posted: 6/6/2008 7:05:14 AM EST
[Last Edit: 6/6/2008 7:35:34 AM EST by shrikefan]

Originally Posted By AeroE:

Originally Posted By shrikefan:

Originally Posted By AeroE:

Originally Posted By VBC:
It ran toward the shooter's direction before it died.


Involuntary muscle movement caused it jump, or dirt kicked up from the bullet impact shoved the little guy back toward the shooter. A jet of high pressure blood and guts might have contributed.



I'm sure any involuntary muscle movement was caused by the 150 gr slug going through it at 3400 fps. The dirt was approx 3-4 ft behind as I recall. The high pressure jet theory may hold some good merit.

Had I known at the time the act was going to be this intriguing I would have found a way to set up high speed camera's and the like. Hind sight is 20/20.


Right there you illustrate why these questions are impossible to answer quickly, or sometimes not at all - the question was posed without providing all the pertinent information.


What we know is that high speed bullets hitting prairie dogs causes them to fly.


Sorry. I saw the projectile weight and velocity were ommited in the OP. My mistake, I was trying cut/paste to un-jack another thread at someones request.
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