Death by Water Bomb
December 13, 2010 6:48 PM Subscribe
How fast would a water balloon have to be going to kill you? Assume it hits you in the head or chest.
Googling "speed of a water balloon death" produced the following: How high to drop water balloon from for it to be deadly
posted by nomadicink at 7:00 PM on December 13, 2010
posted by nomadicink at 7:00 PM on December 13, 2010
It would depend on the mass of the water balloon, the strength of the balloon, and the temperature of the water. Depending on other factors, a more massive balloon could cause far more damage than a less massive one. If the balloon does not rupture upon impact, then its impact would be far more concentrated than a balloon that ruptured on impact, allowing the water to disperse. Temperature is important because a frozen water balloon can be lethal at masses and balloon strengths that would render a liquid balloon harmless.
posted by holterbarbour at 7:05 PM on December 13, 2010
posted by holterbarbour at 7:05 PM on December 13, 2010
IIRC, rapid deceleration (eg a car accident) can kill you by aortic dissection even if the force is perfectly evenly applied to your body. Presumably a balloon hitting you in the chest could do the same thing, but it'd have to be going pretty fast. WAG 80 MPH?
If a balloon hits your head maybe it could cause concussion or a broken neck?
posted by hattifattener at 7:06 PM on December 13, 2010
If a balloon hits your head maybe it could cause concussion or a broken neck?
posted by hattifattener at 7:06 PM on December 13, 2010
Maybe about as fast as you'd need to throw a baseball to make it catch on fire before reaching home plate.
The question is whether the water balloon and the water inside it would disintegrate before reaching the target. I believe it would. Think about how fire hoses were used for crowd control in some of the darker days of the civil rights movement in the US. If that much water under that much pressure didn't crack people's heads, you're not going to do it with a balloon's worth of water.
Unless it's frozen, as scruss says.
posted by alms at 7:08 PM on December 13, 2010
The question is whether the water balloon and the water inside it would disintegrate before reaching the target. I believe it would. Think about how fire hoses were used for crowd control in some of the darker days of the civil rights movement in the US. If that much water under that much pressure didn't crack people's heads, you're not going to do it with a balloon's worth of water.
Unless it's frozen, as scruss says.
posted by alms at 7:08 PM on December 13, 2010
Funny story: I once commanded a small cadre of air cadets in a leadership exercise that involved filling and launching water balloons at another team 100 yards away using one of those surgical tube slingshots. One of my shots hit a commanding officer square in the kidney and... didn't break. I thought it was kind of funny until I saw him crumple. The resulting bruise was bigger than my hand.
So... anecdotally you could have a combination of water balloon parameters (under-filled balloon, compliant target, I don't know) which result in real momentum transfer. I imagine my incident would have been way worse if I had hit the guy in the head.
posted by Popular Ethics at 7:17 PM on December 13, 2010 [4 favorites]
So... anecdotally you could have a combination of water balloon parameters (under-filled balloon, compliant target, I don't know) which result in real momentum transfer. I imagine my incident would have been way worse if I had hit the guy in the head.
posted by Popular Ethics at 7:17 PM on December 13, 2010 [4 favorites]
An anecdote. When I was a kid, my grandmother drove a big ass 1977 Monte Carlo built like a tank. She was driving on a rural road, probably going about 35 mph. She met a car going the opposite direction, but faster (maybe 50 mph?). Just as they passed, someone in the other car lobbed a water balloon out the window, and it hit the front hood/grill area of the Monte Carlo. It shattered the grill, and made a massive dent it the front edge of the hood. The radiator sustained some damage, but luckily wasn't punctured. We counted our blessings that it didn't hit the windshield instead.
posted by kimdog at 7:27 PM on December 13, 2010 [4 favorites]
posted by kimdog at 7:27 PM on December 13, 2010 [4 favorites]
Holy shit, I never thought this experience would actually be...useful.
So after seventh grade we were mostly too cool for the parish picnic (carnival). Instead, we stole one guy's older brother's motorbike, tried to use another guy's dad's welder, etc. Might as well, since everyone in the neighborhood was over at the picnic. So one, guy, let's call him Ivan, had some water balloons from the day before (we always had water balloon fights the day before the picnic) that had...somehow... made it into his parents' deep freeze instead of being used on girls (I suspect he just didn't have the nerve or wasn't cruel enough to soak our female classmates). He also had a dad that was...interesting. First adult male I ever met that had earrings. He wore a kilt, not just on St. Paddy's day, just...when he felt like it. He went to rondez-vouses, which are French fur trapper/Native American/colonial reenactment type things. He also had a water balloon slingshot, cuz hey, why not?
There's a street that has a 45 bend to the right a couple blocks from Ivan's house. To the left and straight ahead, there's about a ten-foot, steep hill, down to a field. There's a guardrail there now, but back then there were just a series of 4x4 posts in the ground, about six feet apart.
There were four of us - myself, Ivan, this kid "Kurt" that was from the next parish over that Ivan knew from the school year he spent over there, and "Matt", this weaselly kid few liked, but he knew how to get pornos for a quarter, so everyone tolerated him. We had the cooler of frozen water balloons, the water baloon slingshot, an old 1970s-sparkly-blue motorcycle helmet, and a catcher's mitt. The slingshot was basically eight feet of extra-heavy-duty surgical tubing bound into a loop, with a handle at each end and a little cloth basket in the middle.
We played the game like this: one guy would be down in the field, wearing the helmet and the catcher's mitt. Two of us would be the "arms" of the slingshot. We would each brace against the 4x4s and hold one end of the slingshot. The fourth guy would pull the slingshot back and launch. What was great was the edge of the road had a curb, so the guy who was launching the balloon could just dig his heels in and lean back until he was laying on the road.
After about two or three catches for each of us, "Kurt" had the great idea - He wanted to catch again, but he wanted to do it on the dead run. So he started at the top of the hill, and he would run down the hill to get super speed, and then we'd launch the water balloon. Only it didn't work like that. The weaselly kid, "Matt"? He let go - he swore it was accidental - while Kurt was still up on top of the hill with us. It hit the back of Kurt's knee and shattered - luckily, that particular balloon hadn't frozen through. KNocked Kurt down the hill, cursing.
Didn't break the leg. Didn't even cause permanent damage to the joint. But we packed up, and went home (Kurt knew it wasn't broken, because he'd broken arms before and knew what that hurt like), and didn't really tell our parents what we were up to.
I re-met Kurt in high school. First thing he said to me, freshman orientation was, "dude, remember the ice balloons? Check out this fuckin' scar!"
posted by notsnot at 7:42 PM on December 13, 2010 [12 favorites]
So after seventh grade we were mostly too cool for the parish picnic (carnival). Instead, we stole one guy's older brother's motorbike, tried to use another guy's dad's welder, etc. Might as well, since everyone in the neighborhood was over at the picnic. So one, guy, let's call him Ivan, had some water balloons from the day before (we always had water balloon fights the day before the picnic) that had...somehow... made it into his parents' deep freeze instead of being used on girls (I suspect he just didn't have the nerve or wasn't cruel enough to soak our female classmates). He also had a dad that was...interesting. First adult male I ever met that had earrings. He wore a kilt, not just on St. Paddy's day, just...when he felt like it. He went to rondez-vouses, which are French fur trapper/Native American/colonial reenactment type things. He also had a water balloon slingshot, cuz hey, why not?
There's a street that has a 45 bend to the right a couple blocks from Ivan's house. To the left and straight ahead, there's about a ten-foot, steep hill, down to a field. There's a guardrail there now, but back then there were just a series of 4x4 posts in the ground, about six feet apart.
There were four of us - myself, Ivan, this kid "Kurt" that was from the next parish over that Ivan knew from the school year he spent over there, and "Matt", this weaselly kid few liked, but he knew how to get pornos for a quarter, so everyone tolerated him. We had the cooler of frozen water balloons, the water baloon slingshot, an old 1970s-sparkly-blue motorcycle helmet, and a catcher's mitt. The slingshot was basically eight feet of extra-heavy-duty surgical tubing bound into a loop, with a handle at each end and a little cloth basket in the middle.
We played the game like this: one guy would be down in the field, wearing the helmet and the catcher's mitt. Two of us would be the "arms" of the slingshot. We would each brace against the 4x4s and hold one end of the slingshot. The fourth guy would pull the slingshot back and launch. What was great was the edge of the road had a curb, so the guy who was launching the balloon could just dig his heels in and lean back until he was laying on the road.
After about two or three catches for each of us, "Kurt" had the great idea - He wanted to catch again, but he wanted to do it on the dead run. So he started at the top of the hill, and he would run down the hill to get super speed, and then we'd launch the water balloon. Only it didn't work like that. The weaselly kid, "Matt"? He let go - he swore it was accidental - while Kurt was still up on top of the hill with us. It hit the back of Kurt's knee and shattered - luckily, that particular balloon hadn't frozen through. KNocked Kurt down the hill, cursing.
Didn't break the leg. Didn't even cause permanent damage to the joint. But we packed up, and went home (Kurt knew it wasn't broken, because he'd broken arms before and knew what that hurt like), and didn't really tell our parents what we were up to.
I re-met Kurt in high school. First thing he said to me, freshman orientation was, "dude, remember the ice balloons? Check out this fuckin' scar!"
posted by notsnot at 7:42 PM on December 13, 2010 [12 favorites]
I imagine the velocity would be much higher than the structural integrity of the balloon itself could ever bear.
Unless as mentioned, you froze the sucker.
posted by bardic at 8:17 PM on December 13, 2010
Unless as mentioned, you froze the sucker.
posted by bardic at 8:17 PM on December 13, 2010
When I was a TA, one of my students was struck in the face by a water balloon, one fired using those slingshots that Popular Ethics describes. He was blinded- permanently, both eyes irreparably damaged.
Not death, but something like death.
posted by ethnomethodologist at 8:29 PM on December 13, 2010 [2 favorites]
Not death, but something like death.
posted by ethnomethodologist at 8:29 PM on December 13, 2010 [2 favorites]
When I was in high school, a girl got hit in the upper abdomen by a water balloon launched from a launcher (sorta like this, I guess). The balloon was not frozen, but she was standing rather close to the launcher. (She was standing on the track in the football stadium; the launcher was being used to send water balloons up into the stand. The kid with the launcher let it go too low, obviously.)
Her spleen was ruptured, an ambulance was called, and it was removed. So she didn't bleed to death. But she could have.
I don't know how fast those launchers can make a balloon go, but it's fast enough to be deadly, depending on where it hits you.
posted by purpleclover at 9:10 PM on December 13, 2010 [2 favorites]
Her spleen was ruptured, an ambulance was called, and it was removed. So she didn't bleed to death. But she could have.
I don't know how fast those launchers can make a balloon go, but it's fast enough to be deadly, depending on where it hits you.
posted by purpleclover at 9:10 PM on December 13, 2010 [2 favorites]
If it hit you in the chest, directly over your heart, and the timing was right, then it wouldn't have to be going very fast at all to kill you. Very rarely, a light blow to the chest in this area can interfere with the heart's rhythm and cause sudden death. The condition is called commodio cordis.
posted by mudlark at 10:36 PM on December 13, 2010
posted by mudlark at 10:36 PM on December 13, 2010
Someone through a water balloon at my friend's windshield when he was going 45 mph and it shattered the glass...
posted by Glendale at 4:08 AM on December 14, 2010
posted by Glendale at 4:08 AM on December 14, 2010
We should page "our" asavage, since a recent mythbusters episode has some info that might be relevant. As part of the "a bug hits a you when driving a motorcycle" myth they figure out how much force, and which part of the body, is most vulnerable..
posted by DreamerFi at 4:44 AM on December 14, 2010
posted by DreamerFi at 4:44 AM on December 14, 2010
Best answer: I saw that episode a few days ago. I think it was 75 pounds of force on the throat, or 100lbs on the chest. So if a filled water balloon weighed 2 pounds and was thrown at 370 meters/second^2 it'd be enough to kill a person if it hit their throat. That's 0.37 kilometers/second, or 1,332 kph, or 828mph. This water balloon sling shot claims 75mph so based on the above I don't think it'd be directly fatal. Now...
Assumptions:
* A filled water balloon weighs 2 pounds, which is just a blind guess. Anyone got one handy they could fill and weigh?
* The required surface area is spread out evenly... Those balloons are pretty big and expand so it'd spread the force of impact out over a lot of space, and the burst would release the water, so half would just flow around the person.
* We're talking about death from a direct strike, not bleeding to death after a strike, etc.
All of which brings up a problem for the Mythbusters episode (or my math), since based on the comments above there's obviously *potentially* fatal damage occurring at lower speeds and forces.
posted by jwells at 6:19 AM on December 14, 2010
Assumptions:
* A filled water balloon weighs 2 pounds, which is just a blind guess. Anyone got one handy they could fill and weigh?
* The required surface area is spread out evenly... Those balloons are pretty big and expand so it'd spread the force of impact out over a lot of space, and the burst would release the water, so half would just flow around the person.
* We're talking about death from a direct strike, not bleeding to death after a strike, etc.
All of which brings up a problem for the Mythbusters episode (or my math), since based on the comments above there's obviously *potentially* fatal damage occurring at lower speeds and forces.
posted by jwells at 6:19 AM on December 14, 2010
I've been hit by one of those three-man launchers. I was probably... 200 meters away from it? [I was on a boat, they were on the shore]. It knocked me down and shoved my glasses up through my eyebrows. They healed okay.
This was at a river festival where people also drop 'water balloons' [not the kind that explode easily, but regular party balloons] from a bridge about 50m up. I've never been hit by one, but have seen numerous people knocked unconscious [while driving a boat in shallow water next to a giant concrete bridge pillar] or knocked right into the water. Apart from the physical trauma, there's two excellent ways to die right there. These balloons would do real damage to the hulls of the boats, too.
People die from being punched.
posted by Acari at 7:47 AM on December 14, 2010
This was at a river festival where people also drop 'water balloons' [not the kind that explode easily, but regular party balloons] from a bridge about 50m up. I've never been hit by one, but have seen numerous people knocked unconscious [while driving a boat in shallow water next to a giant concrete bridge pillar] or knocked right into the water. Apart from the physical trauma, there's two excellent ways to die right there. These balloons would do real damage to the hulls of the boats, too.
People die from being punched.
posted by Acari at 7:47 AM on December 14, 2010
As high-schoolers we climbed to the roof of a friend's 8-story apartment building, with our water balloons, planning to hit some passer-by. After quite some time without a target in range, we decided to aim for a parked car instead. The windshield shattered and the roof was quite visibly caved in. I think we could have broken someone's neck.
posted by StickyCarpet at 7:55 AM on December 14, 2010
posted by StickyCarpet at 7:55 AM on December 14, 2010
Response by poster: Thanks, everyone. I think jwells may have the best answer we're going to get without unethical yet refreshing experimentation.
However, if anyone else wants to take a stab at it, I would accept a water balloon accelerated in a vacuum, so that it doesn't deform or disintegrate, that hits an unprotected human who is also in a vacuum, and who would therefore probably prefer an instantaneous death by water balloon than whatever happens to you in a vacuum (which is another question entirely).
posted by lore at 9:32 AM on December 14, 2010
However, if anyone else wants to take a stab at it, I would accept a water balloon accelerated in a vacuum, so that it doesn't deform or disintegrate, that hits an unprotected human who is also in a vacuum, and who would therefore probably prefer an instantaneous death by water balloon than whatever happens to you in a vacuum (which is another question entirely).
posted by lore at 9:32 AM on December 14, 2010
Response by poster: Also, for anyone reading this thread out of curiosity, I've found that "water balloon injuries" is an illuminating search. Deaths appear to be rare if they happen at all, but temporary or permanent blindness is common enough for watchdog groups to notice.
posted by lore at 9:37 AM on December 14, 2010
posted by lore at 9:37 AM on December 14, 2010
This is a terrifying thread.
posted by Sully at 4:16 PM on December 14, 2010 [1 favorite]
posted by Sully at 4:16 PM on December 14, 2010 [1 favorite]
Best answer: Woah, hold up there jwells. You just converted m/s^2 - a unit of acceleration, to km/hr - a unit of speed. That's a physics foul. The "speed" by itself is not enough to determine how much force a projectile will impart. You need to assume that it will take some distance to stop and from there work out the acceleration.
Lets take your 2 pound balloon traveling at 75mph. If we say it takes 4 inches to come to a complete halt (the diameter of the balloon. This is a total bullshit number - some of the water stops more suddenly, some of the water would continue to travel forwards and sideways, thus not imparting all of its energy into the target. Plus your target would move in the impact too.) you get a deceleration of 5500m/s^2 (a = -v2^2/2*d) which would require a force of over 1000 lb (f=ma)! The assumptions are way too simplistic though. You'd have to know more about how a water balloon transfers it's energy in a collision with a throat or ribcage. I recommend a test program :)
posted by Popular Ethics at 10:13 AM on December 17, 2010
Lets take your 2 pound balloon traveling at 75mph. If we say it takes 4 inches to come to a complete halt (the diameter of the balloon. This is a total bullshit number - some of the water stops more suddenly, some of the water would continue to travel forwards and sideways, thus not imparting all of its energy into the target. Plus your target would move in the impact too.) you get a deceleration of 5500m/s^2 (a = -v2^2/2*d) which would require a force of over 1000 lb (f=ma)! The assumptions are way too simplistic though. You'd have to know more about how a water balloon transfers it's energy in a collision with a throat or ribcage. I recommend a test program :)
posted by Popular Ethics at 10:13 AM on December 17, 2010
(I don't really recommend a test program)
posted by Popular Ethics at 10:17 AM on December 17, 2010
posted by Popular Ethics at 10:17 AM on December 17, 2010
Thank you Popular Ethics. I knew my numbers didn't fit the stories above!
I guess someone will just have to get a force plate and some water balloons and test!
posted by jwells at 11:59 AM on December 17, 2010
I guess someone will just have to get a force plate and some water balloons and test!
posted by jwells at 11:59 AM on December 17, 2010
This thread is closed to new comments.
Because they deform and spread their impact force over a large area, I think a regular water balloon would have to be going unfeasibly fast to do harm.
posted by scruss at 6:58 PM on December 13, 2010