# Limits of Human Acceleration

1. Apr 2, 2013

### Dr Von Braun

Hi, all. I'm trying to ascertain whether it is remotely possible for a human being to survive acceleration from 100 to 7000 mph (essentially, from 0 to Mach 10) in say 5 seconds? 10 even? Assume the mass that of an ordinary man, and perhaps a co-pilot, the vehicle probably a prototype of modern stealth. I think not. And, if this be so, what technical problems stand in the way? (Assume vertical or horizontal acceleration at sea level.) I don't know how many Gs this would produce, but the record seems to be 46. And that bloke wasn't even flying (well, almost) at Mach-1.

I am not a technical person, just doing some research for a book, so please excuse me. Any irrelevance is not meant as irreverence.

Cheers,

VB

2. Apr 3, 2013

### A.T.

Aside of the rocket sled experiments that you probablly know about, there was a sr-71 pilot who survived a plane breakup at mach3. Not sure what the acell. due to air resistance was there.

The key factor here is not how much acceleration the body expieriences, but how evenly the forces are applied to the body. If you put a human into an indestructible water tank, he will survive much greater accelerations. So it is difficult to name a definitive limit.

3. Apr 3, 2013

### SteamKing

Staff Emeritus
With special suits and training, pilots can withstand 9-g accelerations, but I am unable to say for what duration.

If you wanted to accelerate from 100 to 7000 mph at 9g acceleration, it would take approx. 35 sec. to do so.

delta V = 7000 - 100 = 6900 mi/hr * 5280 ft/mi / 3600 s/hr = 10,120 ft/s

delta t = 10120 / (9*32.2) = 34.92 s

4. Apr 3, 2013

### A.T.

SteamKing, the limits you mention are for not blacking out, not mere surviving. Also, the direction relative to your body and body position play a role here.