3 ms·

Vertical acceleration refers to acceleration in the direction of the tracks, right? Some other figures I could find: Shinkansen: 2.6 km/h/s = 0.07g ICE (Germ

by morsch 13y ago

Vertical acceleration refers to acceleration in the direction of the tracks, right? Some other figures I could find: Shinkansen: 2.6 km/h/s = 0.07g ICE (German HSR): 0.5 m/s2 = 0.05g S-Bahn (metro transport): 1 m/s2 = 0.1g Makes sense that metro transport has higher acceleration, as high speed rail spends a lot of time "cruising" at certain speeds, while metro transport is basically always either accelerating or decelerating. I'd guess subways also feature relatively high g-forces. Also interesting: http://en.wikipedia.org/wiki/Orders_of_magnitude_%28acceleration%29 http://en.wikipedia.org/wiki/Orders_of_magnitude_%28accelera...

lmm 13y ago
Vertical as in up-down. You're much more comfortable accelerating forwards-backwards or left-right.
- cma 13y ago
  Then change the orientation of the seats? Without a reference frame you can't tell.
  - modoc 13y ago
    Gravity?
    - dspeyer 13y ago
      Include that in the calculations. There's a certain absolute sideways g-force (decreasable by slowing or straightening), and a certain absolute downwards gravity. These add up to a single total force. So long as the magnitude is at least 1g, there exists a seat orientation such that the passenger feels 1g toward the seat and something on the back. How much you can spin the seat without those movements causing problems is an open question. Airplanes are an encouraging precedent. They often make quite sharp turns at extremely high velocity, but tilt into them such that there's almost no perceived lateral acceleration.
  - jotm 13y ago
    You'd still be going up (from the Earth's surface) and down (towards the Earth)...
- ak217 13y ago
  Is there a source for left/right acceleration being more comfortable than down? My subjective/uneducated guess would actually be that acceleration is most comfortable in the order of: forwards, up, backwards, left/right, down.
JonFish85 13y ago
My understanding of his/her comment was that vertical acceleration is "up & down" (perpendicular to the earth).
- mcguire 13y ago
  I believe specifically, perpendicular to the passenger's horizontal reference frame.
  - IvyMike 13y ago
    Are you saying that laying down on a roller coaster would make it less nauseating? Admittedly I have not tried it but I don't think that would work.
    - gaius 13y ago
      It would, but not for the reason you think: lying on your back activates the mechanism you still have from when you were a baby that stopped you getting motion sickness when you were being carried by your mother. We advise people suffering from seasickness that one thing they can do is lie on their backs, and it often is enough by itself.
      - bashinator 13y ago
        That would also be one reason why motion sickness in microgravity is so pernicious.
brohee 13y ago
I'm think vertical means bumps and dips, for which we really have little tolerance. I don't see i being much of an issue for hyperloop, as varying height of the pillars is pretty easy...

by morsch 13y ago

lmm 13y ago

Vertical as in up-down. You're much more comfortable accelerating forwards-backwards or left-right.

cma 13y ago
Then change the orientation of the seats? Without a reference frame you can't tell.
- modoc 13y ago
  Gravity?
  - dspeyer 13y ago
    Include that in the calculations. There's a certain absolute sideways g-force (decreasable by slowing or straightening), and a certain absolute downwards gravity. These add up to a single total force. So long as the magnitude is at least 1g, there exists a seat orientation such that the passenger feels 1g toward the seat and something on the back. How much you can spin the seat without those movements causing problems is an open question. Airplanes are an encouraging precedent. They often make quite sharp turns at extremely high velocity, but tilt into them such that there's almost no perceived lateral acceleration.
- jotm 13y ago
  You'd still be going up (from the Earth's surface) and down (towards the Earth)...
ak217 13y ago
Is there a source for left/right acceleration being more comfortable than down? My subjective/uneducated guess would actually be that acceleration is most comfortable in the order of: forwards, up, backwards, left/right, down.

JonFish85 13y ago

My understanding of his/her comment was that vertical acceleration is "up & down" (perpendicular to the earth).

mcguire 13y ago
I believe specifically, perpendicular to the passenger's horizontal reference frame.
- IvyMike 13y ago
  Are you saying that laying down on a roller coaster would make it less nauseating? Admittedly I have not tried it but I don't think that would work.
  - gaius 13y ago
    It would, but not for the reason you think: lying on your back activates the mechanism you still have from when you were a baby that stopped you getting motion sickness when you were being carried by your mother. We advise people suffering from seasickness that one thing they can do is lie on their backs, and it often is enough by itself.
    - bashinator 13y ago
      That would also be one reason why motion sickness in microgravity is so pernicious.

brohee 13y ago

I'm think vertical means bumps and dips, for which we really have little tolerance. I don't see i being much of an issue for hyperloop, as varying height of the pillars is pretty easy...