Will the pl... helicopter take off?

[ultimatebob]

Dammit... does somebody have an e-mail address for the Mythbusters?

 

[SSSnail]

The choppa will take off.

There is no force to counter the lift, the only thing the turntable will do is countering the directional spinning of the choppa's blades.

 

[Throckmorton]

Depends on which way the turntable spins

 

[SlitheryDee]

Originally posted by: SSSnail
The choppa will take off.

There is no force to counter the lift, the only thing the turntable will do is countering the directional spinning of the choppa's blades.

Then what's creating the lift?

 

[Triumph]

Assume that the turntable spins clockwise at some speed, say 10 rpm. Assume that the helicopter is able to turn its own blade, also at 10 rpm, but counterclockwise. The net velocity of the blade relative to the air around the blade would be zero. Thus no lift.

 

[randay]

well... a lot of people here dont understand how a helicopter works... I dont blame them, its a complicated machine.

consider the tail rotor for a moment, it acts to counter the torque from the main rotor. in this turn-table nonsense it would also act to counter the torque from the turn-table. depending on the fricton between the landing gear and the surface of the turn-table, the helicopter might easily take off, or not, or cause a horrible crash.

also, is the DJ allowed to play techno? can he scratch?

 

[spidey07]

Originally posted by: 2Xtreme21

Originally posted by: Brainonska511

Originally posted by: 2Xtreme21

Originally posted by: spidey07

Originally posted by: 2Xtreme21
Centrifugal "force" FTW. The helicopter would be flung off the turntable in a matter of seconds.

not if it's center of gravity was on the axis.

That would also assume the chopper is exactly symmetrical and it's front half has exactly the same amount of mass as its back half. Helicopters need to be more massive in the front in order to fly.

This scenario would be completely impossible with any "regular" helicopter.

The *centripital* force would not knock the helicopter away if you had a turntable large enough that you could call the helicopter a "point" (like if you had a helicopter on a turntable with the radius of the Earth).

It is not centripetal as that would be the actual force pulling an object toward the center of a more massive one (a la why the moon stays in orbit around the earth). I quoted "centrifugal" because it is not an actual force, but rather the noticeable effect of the acceleration of the object moving in a circle being pushed OUTWARD.

As I said before-- if the mass of the object is exactly uniform on both sides of the center "point," the helicopter itself would just spin and would be able to take off. Though practically speaking, a helicopter will not be uniform on both sides of the center point. Thus, due to the unequal distribution, the "centrifugal force" caused by the rotating turntable will push the unequally massive helicopter away from the center of the turntable until it is flung off of it.

Do you even know what center of gravity is?

If the center of gravity is on the axis of the turn table then the mass on every side in all 3 diminsions is exactly equal. As such no helicopter flying apart, just rotating perfectly balanced.

 

[lozina]

No. the pilots would pass out from being spun that fast

 

[Demon-Xanth]

If the helicopter could be rotated fast enough that the air speed of the blades is 0 the helicopter would not take off, however the pilot's lunch would.

 

[SSSnail]

Originally posted by: SlitheryDee

Originally posted by: SSSnail
The choppa will take off.

There is no force to counter the lift, the only thing the turntable will do is countering the directional spinning of the choppa's blades.

Then what's creating the lift?

There are two forces.

 

[IronWing]

What if the chopper is a K-MAX?

 

[TheVrolok]

To find out, we'll have to.. get to tha choppah!

 

[911paramedic]

Uh, no.

If they were spinning at the same speed you could touch the rotor blade with your finger. (==no lift generated)

 

[AccruedExpenditure]

No, because those are numarks... if it was a technics turntable you might have a shot

 

[Jeff7]

Is the helicopter resting on swiveling, frictionless wheels? If yes, it takes off. If no, it spins wildly and remains on the turntable.

 

[manlymatt83]

Originally posted by: Cold Steel
It will take off.

No, it won't.

 

[manlymatt83]

Originally posted by: Demon-Xanth
If the helicopter could be rotated fast enough that the air speed of the blades is 0 the helicopter would not take off, however the pilot's lunch would.

Correct.

 

[dds14u]

This would be same as the plane question if:

The plane had no wheels and was resting on a moving runway.

I would say 'no' for the helicopter taking off provided everything was centered.

 

[91TTZ]

"If it's R! then please lock. "

It's a R

 

[Indolent]

Originally posted by: spidey07

Originally posted by: 2Xtreme21

Originally posted by: Brainonska511

Originally posted by: 2Xtreme21

Originally posted by: spidey07

Originally posted by: 2Xtreme21
Centrifugal "force" FTW. The helicopter would be flung off the turntable in a matter of seconds.

not if it's center of gravity was on the axis.

That would also assume the chopper is exactly symmetrical and it's front half has exactly the same amount of mass as its back half. Helicopters need to be more massive in the front in order to fly.

This scenario would be completely impossible with any "regular" helicopter.

The *centripital* force would not knock the helicopter away if you had a turntable large enough that you could call the helicopter a "point" (like if you had a helicopter on a turntable with the radius of the Earth).

It is not centripetal as that would be the actual force pulling an object toward the center of a more massive one (a la why the moon stays in orbit around the earth). I quoted "centrifugal" because it is not an actual force, but rather the noticeable effect of the acceleration of the object moving in a circle being pushed OUTWARD.

As I said before-- if the mass of the object is exactly uniform on both sides of the center "point," the helicopter itself would just spin and would be able to take off. Though practically speaking, a helicopter will not be uniform on both sides of the center point. Thus, due to the unequal distribution, the "centrifugal force" caused by the rotating turntable will push the unequally massive helicopter away from the center of the turntable until it is flung off of it.

Do you even know what center of gravity is?

If the center of gravity is on the axis of the turn table then the mass on every side in all 3 diminsions is exactly equal. As such no helicopter flying apart, just rotating perfectly balanced.

I was suprised it took this many posts for someone to point this out.