darxus: (Default)
darxus ([personal profile] darxus) wrote2004-11-15 05:13 pm
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How fast do you have to go to achieve orbit at sea level ?

[identity profile] ex-absurdmin176.livejournal.com 2004-11-15 02:51 pm (UTC)(link)
you can't orbit at sea level. Too much stuff in the way. :)

[identity profile] ex-absurdmin176.livejournal.com 2004-11-15 02:54 pm (UTC)(link)
or did you mean escape velocity? In that case its about 7 miles per second. Not sure how drag affects it.

[identity profile] ert.livejournal.com 2004-11-15 02:55 pm (UTC)(link)
How fast does one have to go, or how fast do I have to go?

[identity profile] superfinemind.livejournal.com 2004-11-15 03:21 pm (UTC)(link)
Isn't it more than seven for elliptical orbit and more than eleven for escape? miles per second, i think. i don't really remember.

[identity profile] craig-r-meyer.livejournal.com 2004-11-15 09:56 pm (UTC)(link)
Mach 25. That's what it is at LEO, and it's about the same down low. Of course, you'll need a lot more thrust to stay at that speed in the atmosphere.

[identity profile] temalyen.livejournal.com 2004-11-15 10:03 pm (UTC)(link)
I think you'd end up hitting stuff if you tried to orbit at sea level.

However, if we assume you're talking about a hypothetical perfectly smooth "pool ball" planet.. well, I have no idea. I actually spent 10 minutes trying to find this on the web, but couldn't find a thing. I thoguht of trying to calculate it myself, but I don't know jack about physics. (Though I can discuss theoretical physics, I'm useless with the actual math of physics.)

Though I did find the following interesting fact: You'd have to travel at about 3% of lightspeed to make the signals on a cell phone have a doppler effect great enough to render the cell phones inoperable. (assuming you're on a 900mhz phone.)

That seems like something that'd amuse you, though I am unsure why I think that.

[identity profile] cyron-lj.livejournal.com 2004-11-16 05:04 am (UTC)(link)
How much thrust do you need to make a brick fly?