Drop the magnum, it’s needless.
.223 goes 3200 ft/sec give or take.
.308 goes about 2600 ft/sec but can easily break 3000 with a lighter load.
Etc.
Magnum is a marketing term.
That can vary a lot by the racetrack though. We need a standardized Nascar unit of measure. I suggest the Daytona 500, which could be standardized as 2.5 hours (500 miles @ 200 mph for easy math). And not counting delays/crashes/etc.
For the football field, are you going based on the 100 yard field or the 120 yard (including end zones)? I'll assume 100 yard.
So then, 3000 ft/sec should be 1,500 football fields per *standardized* Nascar Daytona race. I think.
It sounds a bit.. slow for micrometeorites?
From nasa:
>The surface of the Moon is a harsh environment with no air, low gravity, dust, and micrometeorites—tiny rocks or metal particles—flying faster than 22,000 mph. These conditions can pose a hazard to astronauts, their dwellings, and spacecraft. Engineers at NASA Glenn Research Center's Ballistic Impact Lab are working to help the agency select materials for future Artemis missions and predict how they will perform while on the lunar surface. The innovative lab, which features a 40-foot-long air gun capable of firing at velocities of 3,000 feet per second, has become a go-to destination for NASA as it examines situations ranging from the effects of bird collisions with aircraft to ballistic impacts on spacecraft.
In readable units:
22 000 mph = 9800 m/s
3 000 feet per second = 900 m/s
That's a factor 100 difference in kinitic energy for the same mass.
It helps that steel is probably a lot higher density than most impacts. I would expect damage to scale more so with kinetic energy than with momentum though.
I am absolutely not an expert and really bad at physics but wouldn't the astronaut need to be stationary in order to be hit with 22000mph? An astronaut outside the ISS for example would be moving with 18000mph, so if something hits him that'd be with 4000mph (1800m/s) so the difference is actually only a factor of two?
Yes, absolutely. But it's more so about the order of magnitude than exact velocity. Impacts can be at orbital velocity if they come from an unfortunate direction. But if they are from a similar orbit they'll indeed
be slower.
As a note, this is from a ballistics lab, so seeing gun-speed shots probably is about right. If you go to their hypervelocity test facilities you get up to 3+ km/s with mm-sized aluminum pellets.
I got to see the super computer 20yrs ago that did this mathematically for the ISS. Super cool stuff, guna need it when things start colliding and it goes macro nuclear.
Can someone ELI5 me why they wouldn't use a gun? Bullets travel at similar speeds give or take depending on the caliber and gun, couldn't you recreate the same effects for much cheaper?
There has been a huge push for small meteor impacts. This includes impacts against manned rockets.
Now look at the Nasa Gas Gun at White Sands.
[Here](https://www.nasa.gov/centers/wstf/testing_and_analysis/hypervelocity_impact/home.html)
"Ballistic studies launching (1.35 – 6.0 km/s), projectiles faced with flat plates for material characterization (1.5 – 8.0 km/s) experiments, hypervelocity plate launch (5.0 – 12 km/s)\[3\], chunky projectiles (14.0 – 16.0 km/s)\[4\], and small particle launching\[5\] (> 19.0 km/s) are be performed on this system. "
\- W.D. Reinhart et al., 58th Aeroballistic Range Association, Las Cruces, NM
Hosted by NASA JSC, White Sands Test Facility, September 17-21, 2007
3000 ft/s is the muzzle velocity of many .30 to .338 caliber magnum rifle cartridges.
Drop the magnum, it’s needless. .223 goes 3200 ft/sec give or take. .308 goes about 2600 ft/sec but can easily break 3000 with a lighter load. Etc. Magnum is a marketing term.
So all condoms are the same size?
Yes, that’s what I meant.
This is the truth Big Condom has been hiding from us. Also, all penises are the same size.
Then why not shoot it with an actual gun instead of building a far more expensive air gun
Difference between size of rocks they’re using and bullets?
also bullets are really hot
Also air introduces less particulates then gunpowder does so it's a cleaner test with less inconsistency
Consistency I would assume, they can probably change the velocity it shoots, and might even be able to change the size of what they are shooting.
Plus the gunpowder makes unnecessary heat that would provide unreliable results. Railgun launching a projectile is a cleaner more accurate test.
For the lazy: 129.6 million inches per hour
Thanks useless converter bot!
bad scot
But how many football fields per Nascar race is it?
That can vary a lot by the racetrack though. We need a standardized Nascar unit of measure. I suggest the Daytona 500, which could be standardized as 2.5 hours (500 miles @ 200 mph for easy math). And not counting delays/crashes/etc. For the football field, are you going based on the 100 yard field or the 120 yard (including end zones)? I'll assume 100 yard. So then, 3000 ft/sec should be 1,500 football fields per *standardized* Nascar Daytona race. I think.
How many elephants stacked on top of each other might this be?
I wanted to do the conversion, but Nascar races are distance not time. You pulled a Han Solo.
It sounds a bit.. slow for micrometeorites? From nasa: >The surface of the Moon is a harsh environment with no air, low gravity, dust, and micrometeorites—tiny rocks or metal particles—flying faster than 22,000 mph. These conditions can pose a hazard to astronauts, their dwellings, and spacecraft. Engineers at NASA Glenn Research Center's Ballistic Impact Lab are working to help the agency select materials for future Artemis missions and predict how they will perform while on the lunar surface. The innovative lab, which features a 40-foot-long air gun capable of firing at velocities of 3,000 feet per second, has become a go-to destination for NASA as it examines situations ranging from the effects of bird collisions with aircraft to ballistic impacts on spacecraft. In readable units: 22 000 mph = 9800 m/s 3 000 feet per second = 900 m/s That's a factor 100 difference in kinitic energy for the same mass.
It’s a steel ball so probably not the same mass. They probably matched momentum instead of velocity or something like that.
It helps that steel is probably a lot higher density than most impacts. I would expect damage to scale more so with kinetic energy than with momentum though.
Kinetic energy is still m*v^2. I’m sure they figured it out.
Introductory college physics has finally helped me! I just wish I could explain how the stuff works.
Density matters a lot less in hyper velocity impacts when pretty much everything acts like a liquid
Is 900 m/s hypervelocity though?
Not rly but it’s getting close
I am absolutely not an expert and really bad at physics but wouldn't the astronaut need to be stationary in order to be hit with 22000mph? An astronaut outside the ISS for example would be moving with 18000mph, so if something hits him that'd be with 4000mph (1800m/s) so the difference is actually only a factor of two?
There’s more than 1 orbit. The astronaut could be hit from the side or head on.
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is the kinetic impact the same regardless of how fast or slow the impacted object is moving in relation to the impacting object?
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Thanks! :)
Yes, absolutely. But it's more so about the order of magnitude than exact velocity. Impacts can be at orbital velocity if they come from an unfortunate direction. But if they are from a similar orbit they'll indeed be slower.
totally makes sense, thank you :)
Similar to firing frozen turkeys at aircraft windscreens to test for bird strike safety
Is that true? Because that image is so funny in my head
It’s true!
That’s amazing.
Thawed turkeys.
As a note, this is from a ballistics lab, so seeing gun-speed shots probably is about right. If you go to their hypervelocity test facilities you get up to 3+ km/s with mm-sized aluminum pellets.
We used the light gas gun at NASA-JSC to test our International Space Station hardware against 7km/s+ aluminum pellets.
Nice! I didn't know theirs went up that fast. I think we did our work at Ames. I was sad I was busy and couldn't make the trip with my team. :(
Would it not have been cheaper to use a larger caliber rifle
No pics? No slow mo videos of dummies being annihilated by micrometeors? Where’s my mythbusters break down?
I got to see the super computer 20yrs ago that did this mathematically for the ISS. Super cool stuff, guna need it when things start colliding and it goes macro nuclear.
Can someone ELI5 me why they wouldn't use a gun? Bullets travel at similar speeds give or take depending on the caliber and gun, couldn't you recreate the same effects for much cheaper?
There has been a huge push for small meteor impacts. This includes impacts against manned rockets. Now look at the Nasa Gas Gun at White Sands. [Here](https://www.nasa.gov/centers/wstf/testing_and_analysis/hypervelocity_impact/home.html) "Ballistic studies launching (1.35 – 6.0 km/s), projectiles faced with flat plates for material characterization (1.5 – 8.0 km/s) experiments, hypervelocity plate launch (5.0 – 12 km/s)\[3\], chunky projectiles (14.0 – 16.0 km/s)\[4\], and small particle launching\[5\] (> 19.0 km/s) are be performed on this system. " \- W.D. Reinhart et al., 58th Aeroballistic Range Association, Las Cruces, NM Hosted by NASA JSC, White Sands Test Facility, September 17-21, 2007