hal@finney.org wrote:
> Spike writes:
> ...
> > If it is going sufficiently fast, the centripetal acceleration
> > equals the acceleration due to gravity at that point, so the
> > occupants of the car are temporarily wieghtless. If the
> > tunnel is any steeper, the occupants experience negative Gs.
>
> I don't believe this is correct. Centripetal acceleration only applies
> to circular motion, and the car is going in a straight line... Hal
Doh! Hal is right. I incorrectly remembered having done these
calcs a few months ago, and I had a straight tunnel tangent to
a circular tunnel at some depth. My calculation of depth would
work if the tunnel went down at 35 degrees, met up with a
circular tunnel at a constant depth in which the train car would
be weightless, orbitting inside the planet, then later tangent
to another straight tunnel going back up to the surface.
Thanks Hal! spike
This archive was generated by hypermail 2b30 : Fri Oct 12 2001 - 14:40:58 MDT