Singapore flight turbulence

[Brigadier]

It would have to fall faster than a stone, for the passengers to effectively fall slower, and hit the ceiling.

Not if the plane moved upwards - rapidly enough - first.

 

[fixitflav]

They most certainly do, if the vehicle drops like a stone, yes.

Sorry, they don't. Lift and objects both fall with acceleration g.

 

[fixitflav]

Not if the plane moved upwards - rapidly enough - first.

If an object is projected upwards, it experiences downward acceleration g at all times, not greater. That's why the velocity decreases till it's zero at maximum height, then increases as it falls back to the ground.

 

[fixitflav]

The plane isn't just falling, it can be pushed down a faster rate than that in certain circumstances.

Yes, it would have to be. That's what I was surmising in the original post.

 

[fixitflav]

I would hazard a guess more of a tail kick occurred could be wrong, the plane hitting turbulent air causing an oscillation affected more towards the rear of the plane, a sudden hump off air kicking the rear up and sharply down causing untethered passengers to accelerate towards lockers.

Good point, maybe the front rows of seats get it, but not the back, or vice versa.

 

[Brigadier]

If an object is projected upwards, it experiences downward acceleration g at all times, not greater. That's why the velocity decreases till it's zero at maximum height, then increases as it falls back to the ground.

Not if the overhead lockers get in the way first..........

 

[fixitflav]

Not if the overhead lockers get in the way first..........

But the passenger wouldn't rise unless the plane was falling at greater than g, is the point I'm making. And it must be a big effect, to cause the damage it did, people's heads breaking overhead lockers etc.

 

[Brigadier]

But the passenger wouldn't rise unless the plane was falling at greater than g,

Of course they would.

Plane in level flight.
Passenger sitting happily, without lapbelt on.
Overhead locker is 1m above passenger's noggin.

Plane suddenly lurches upwards at 2g, for 1 second, then resumes level flight.
Plane has gone from 0m/s (vertically), to c. 20m/s (vertically) in 1s, then back to 0m/s.
The passenger does the same, except that they only go back to 0m/s when their head hits the overhead lockers.

 

[Notch7]

f*****g scary whatever the physics

 

[fixitflav]

Of course they would.

Plane in level flight.
Passenger sitting happily, without lapbelt on.
Overhead locker is 1m above passenger's noggin.

Plane suddenly lurches upwards at 2g, for 1 second, then resumes level flight.
Plane has gone from 0m/s (vertically), to c. 20m/s (vertically) in 1s, then back to 0m/s.
The passenger does the same, except that they only go back to 0m/s when their head hits the overhead lockers.

The plane accelerating upwards first has nothing to do with it. If that happens, the passenger is pressed harder on to the seat.

If it accelerates downwards at greater than g, the passenger rises off the seat, that's what I've said all along. The question is - what causes the downward acceleration? Downward air current most likely. Maybe in turbulent conditions there's upward and downward acceleratiion in quick succession, the downward causing more trouble.

The behaviour of a thrown stone in still air is irrelevant.

 

[fillyboy]

what causes the downward acceleration? Downward air current most likely.

Or no air current at all. A black hole.

 

[Brigadier]

The plane accelerating upwards first has nothing to do with it. If that happens, the passenger is pressed harder on to the seat.

And when the plane stops accelerating upwards?

What happens to the passenger?

 

[fixitflav]

And when the plane stops accelerating upwards?

What happens to the passenger?

They just revert to putting their normal weight on the seat.

 

[fixitflav]

Or no air current at all. A black hole.

If all the air suddenly disappears, the plane falls at g. If it goes into a black hole there are worse thinfs to worry about.

 

[Brigadier]

They just revert to putting their normal weight on the seat.

If that is the case, how is it possible to throw anything?