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scottryan1 · Feb 4, 2011, 12:30 AM

Unknown008 · Feb 4, 2011, 03:03 AM

Well, I don't know, but when I used Google, I didn't come up with anything directly, but this:

Astronauts use a centrifuge to simulate the acceleration of a rocket launch. The centrifuge takes 20.0 s to speed up from rest to its top speed of 1 rotation every 1.40 s. The astronaut is strapped into a seat 7.80 m from the axis.

From this, you can work out the speed which happens to be:

$v = 7.8\times \frac{2\pi}{1.4} = 35 m/s$

Hm... that's not much.

Maybe you're looking for the acceleration astronauts can withstand?

$a = 7.8 \times $\frac{2\pi}{1.4}$^2 = 157 m/s^2$

This is about 16 times the acceleration due to gravity!

ebaines · Feb 4, 2011, 11:57 AM

Since you asked about speed, and not acceleration, you should understand that speed is relative. There are no issues with respect to what a person can "withstand" regarding one's speed relative to another. It's change in speed, or acceleration, that is an issue, as Unk described. But as for some speed records:

1. The speed with which astronauts returning from the moon as measured relative to the earth is max about 40000Km/Hr, or 11.1 Km/s.

2. The earth orbits around the sun at about 30 Km/s.

3. The solar system moves through the Milky Way Galaxy at about 220 Km/s.

4. The relative velocity between galaxies can vary quite a bit, but astronomers have observed that we are moving at a speed of about 75,000 Km/s relative to the most distant observed galaxies.

So there you go - you yourself are moving at 75000 Km/s as measured by someone on that distant galaxy - yet you have no issue "withstanding" that at all! The only true limit is that nothing can move faster than the speed of light, or 300,000 Km/s.