Ballistics Experts: Question.

Is your marriage in trouble again...?

 

See http://www.aeroballisticsonline.com/ballistics/riflings.html towards the bottom of the page

 

Yes, they really do spin that fast. That is exactly why to achieve good accuracy a bullet has to be made with great precision. Can you imagine the the imbalance that would be created if the jacket material was inconsistant in wall thickness and the lead core was off center? That's one reason why good quality target (rifle) bullets (bullet only) are so expensive. It is also the reason that in some calibers of long range target rifles (we are always trying for higher velocities) the bullets blow up. It usually happens about 5-15 yards beyond the muzzle.

 

Simply put, yes it is possible and readily quantifiable.

 

The electrons in an atom go a bit faster than that.




A good puzzler would be if the outer ridge of your car tire is spinning at 55mph what is the inner most inch spinning at?

 

NICMOS Cryocooler (NCC) Installation:
Astronauts retrofitted an existing but dormant instrument called the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) with a new, experimental cooling system to return it to active duty. NICMOS was placed on Hubble in 1997 but became inactive two years later, after depleting the ice it needed to cool its infrared detectors. By fitting NICMOS with the experimental cryogenic system, NASA hopes to re-cool the detectors to -334°F (-203°C or 70 K) revive its infrared vision, and extend its life by several years.

The super-quiet cooler uses ultra-high speed microturbines, the fastest of which spins at over 200,000 rpm (over 50 times the maximum speed of a typical car engine). Hubble's engineering team successfully demonstrated this technology in 1998 aboard STS-95 in the first on-orbit test of a high-performance, high-efficiency, mechanical cryocooler.

 

How fast does a dental drill spin?
Turbo charger Impeller?
Turbo molecular vacuum pump impeller?

I don't know the exact speeds these turn but they are high rpm devices.

Erich

 

http://www.penglim.com.tw/g3.htm

Medical/dental are over 400,000 rpm.

 

Now were talking, the development of 1,000,000 rpm microengines. We can start a whole new torque vs horsepower discussion!

http://users.wpi.edu/~chslt/docs/pdf/rjp/Adv%20opt%20meth%20microeng%20rot%20high%20speeds%20-%20SEM2000.pdf

 

55mph?