Understanding Zero-G Flight Physics: How Men Navigate Curved Paths in Airplanes

[Aeronautic Freek]

Men in airplane goes in curve path during ZeroG..So how men do not touch neither walls of airplane if plane fly in curve path?
Where is now centripetal force force which drive men in curved path?

 

[russ_watters]

Where is now centripetal force force which drive men in curved curved path.

It's gravity.

[and it is primarily not centripetal.]

 

[A.T.]

So how men do not touch neither walls of airplane if plane fly in curve path?

The men move on the same curved path as the plane.

 

[Ibix]

Get yourself and two friends and stand shoulder to shoulder. Throw balls simultaneously forwards at the same speed and upward angle. Why don't the three balls collide? Because they're traveling at the same velocity and the same gravity is pulling them in the same direction. Ditto the guys in the plane.

 

[Aeronautic Freek]

The men move on the same curved path as the plane.

yes I know ,but why when men leave floor not hit on upper part of airplane walls,plane goes in "circle" so how plane transfer force to drive men in circle?with air inside?

 

[DaveC426913]

yes I know ,but why when men leave floor not hit on upper part of airplane walls,plane goes in "circle" so how plane transfer force to drive men in circle?with air inside?

The plane doesn't go in a circle.

A falling person follows a parabolic (ballistic) path to the ground.
If the plane is careful to dive along that parabolic path, the person inside will not experience any relative motion with respect to the plane. He will appear to float.

It's exactly like an elevator in free fall, just without the horizontal component.

 

[russ_watters]

...so how plane transfer force to drive men in circle?with air inside?

It's still gravity. The plane is not applying a force on the people inside.

 

[Ibix]

The men are initially sitting on the floor and are accelerated to flight speed by the plane. Once the plane enters its ballistic path, the men share its initial diagonally upwards velocity. They are no longer pushed by the plane because it is decelerating at the same rate they are - they all follow the same ballistic trajectory, just like the balls in my earlier example. The passengers can then drift around the cabin by giving themselves a slight extra acceleration by kicking off the walls.

 

[A.T.]

yes I know ,but why when men leave floor not hit on upper part of airplane walls,plane goes in "circle" so how plane transfer force to drive men in circle?with air inside?

Their paths have the same shape, so there is no relative movement, so they don't collide.

 

[berkeman]

but why when men leave floor not hit on upper part of airplane walls

As already said, the plane follows a parabolic arc down, just like the occupants would follow in free-fall given their initial forward and downward velocities.

Maybe this will help -- my ex-wife flew on that "Vomit Comet" as part of her work for NASA, and she told me afterwards about a MacGyver setup that the pilots used to fine tune their downward parabolic path to set and hold zero-g in the aircraft on the descents. They had a metal nut hanging from the ceiling on a string in the cockpit, and as they started their dive, they watched the nut. They initially dove enough to start to make the nut float (the string was no longer taut), and then fine tuned their dive profile to keep the metal nut floating in the cockpit.

So what the pilots were doing to keep the nut floating in the cockpit was the same thing that was happening to the occupants in the main body of the plane. Everything was floating at zero-g in the plane, except for the pilots who were obviously belted in tightly in the cockpit like all good pilots.

 

[DaveC426913]

They had a metal nut hanging from a string in the cockpit from the ceiling

I love analogue computation.

 

[A.T.]

... so how plane transfer force to drive men in circle? with air inside?

Maybe your misconception is that the hull of the airplane is shielding the men from gravity, so the downwards force must be transmitted to them via contact forces? Gravity acts on the men inside the plane, just as if the plane wasn't there. The plane just needs to fall with them, so it's walls are not in the way.

In more detail: The plane cannot just rely on gravity alone, because of air resistance. It hast to tune the engines to exactly cancel the drag. For the men inside the air falls with them, so they don't approach terminal velocity like skydivers.