Will the plane take off?

[Yenn]

if the propeller develops sufficient air flow over the wings the craft will fly, the conveyor belt be it locked, running forward or running backward is just a distraction for the mythbusters audience.

This sounds as if you are saying that the propeller can produce airflow over the wings and the plane will fly, even if there is no forward motion in relation to the surrounding air mass. I don't think that has ever been achieved in practice.

[Flying Binghi]

This sounds as if you are saying that the propeller can produce airflow over the wings and the plane will fly, even if there is no forward motion in relation to the surrounding air mass. I don't think that has ever been achieved in practice.

 

Yeah!..... yer not thinking of the added gyro effect of fast spinning wheels. After wheels spin up to max revolutions, touch one brake slightly to add a sudden sideways movement to the aircraft which makes the resulting gyro effect fling the aircraft into the air thus allowing time for the propellor effect to aid with adding forward motion, and off yer fly....................

 

 

 

 

?

 

 

 

 

 

 

 

 

.

[facthunter]

Yeah Pigs fly too, Just, Piaggio. Nev

[Flying Binghi]

Yeah Pigs fly too, Just, Piaggio. Nev

 

Them Pigs used to look good on afterburner...?

 

 

 

 

.

[facthunter]

Referring to the twin piston pushers in PNG in the 60's. Nev

[kgwilson]

It depends on how you interpret the question. If there is nothing holding the aircraft back the thrust of the prop will easily overcome the drag produced by the wheels turning at twice the normal speed by the time sufficient lift is produced by the airflow to get the aircraft in the air. If the premise is that the aircraft stays stationary and just the conveyor is moving backwards at normal takeoff speed the aircraft won't go anywhere. Simple.

[Student Pilot]

Agreed KG, no fly.

[Bruce Tuncks]

The question has not been clearly formulated. Saying that the conveyor moved backwards at the exact speed of the plane doesn't say if the speed of the plane was relative to the conveyor or the air.

In the latter case if the plane were a Jabiru and the airspeed was 80 knots and the conveyor was moving backwards at 80 knots then of course it would fly. A speedo running from the wheels would say the speed was 160 knots.

If the plane had this kind of speedo ( like a car) and it was doing 80 knots wheel speed and the conveyor was running backwards at 80 knots then the airspeed would be zero and it wouldn't fly.

[Bruce Tuncks]

Here is a better one... 2 brothers had a bunch of Jabirus for sale.... a whole flock of them. They met a buyer who agreed to pay the same dollars for each one as there were jabirus in the flock. He paid them in $1 coins.

The brothers carried the coins home in a bucket and proceeded to share them out. The older started by taking ten, then the younger took ten and they continued like this until it was the younger brother's turn but there were not ten left. He took what there were.

They agreed that the older brother needed to pay the balance, so he did... How much did he owe?

 

There is a correct answer!

[kgwilson]

There were an odd number of Jabirus. $10.00

Edited April 7, 2020 by kgwilson

[Thruster88]

Here is a better one... 2 brothers had a bunch of Jabirus for sale.... a whole flock of them. They met a buyer who agreed to pay the same dollars for each one as there were jabirus in the flock. He paid them in $1 coins.

The brothers carried the coins home in a bucket and proceeded to share them out. The older started by taking ten, then the younger took ten and they continued like this until it was the younger brother's turn but there were not ten left. He took what there were.

They agreed that the older brother needed to pay the balance, so he did... How much did he owe?

 

There is a correct answer!

 

$1 or $4 depending on the price which must have been poor if the coins fitted in one bucket ?

[onetrack]

I wouldn't want to fly in any Jabiru that was bought with just a bucket of coins! - even if they were $2 coins!!

[Bruce Tuncks]

Here's a BIG clue... if there were x jabirus selling for x dollars each, there were x squared dollar coins on the table. well at least before they began the divvying.

[GraemeK]

Answer is $4 - and the price per plane could be 6, 14, 16, 24, 26, 34, 36, 44, 46, etc.

[Thruster88]

Answer is $4 - and the price per plane could be 6, 14, 16, 24, 26, 34, 36, 44, 46, etc.

 

If the price was 12 there would be $4 ? left in the bucket so big bro would have to pay $1

I am a maths retard disregard.

Edited April 7, 2020 by Thruster88

[GraemeK]

If price was $12, then $144 in bucket. Each takes out 7 lots of $10, leaving $4 which is not enough for big bro to take out his $10. So cannot be $12.

 

Using $14 as example, there is $196 in bucket. Each takes out 9 lots of $10 ($180 total), leaving $16. Older brother takes his $10, leaving $6 in the bucket. Older bro owes younger bro $4 to make up his $10.

 

I have made the assumption that "the balance" means to make the younger up to $10 - if we assume it means to equalise them, then he pays out $2 in all cases.

Edited April 7, 2020 by GraemeK

[Bruce Tuncks]

You got it GraemeK ! You have hereby won a glass of red anytime you come to Gawler. Here's the explanation...

If the number is a square AND the number of tens is ODD then the last number is always a 6. ( i dunno if this has ever been proven but you can check for more than the biggest bucket you can imagine )

So the older brother might have paid $4 if he was silly, or $2 to equalize.

[GraemeK]

Interestingly to note that pattern of n4, n6 (06, 14, 16, 24, 26, 34, 36, ...) - must be a reason, I've tested it up into the thousands, a new challenge to work out why!

[kasper]

It depends on how you interpret the question. If there is nothing holding the aircraft back the thrust of the prop will easily overcome the drag produced by the wheels turning at twice the normal speed by the time sufficient lift is produced by the airflow to get the aircraft in the air. If the premise is that the aircraft stays stationary and just the conveyor is moving backwards at normal takeoff speed the aircraft won't go anywhere. Simple.

But that’s not the possible case ... aircraft wheels are not powered. Therefore the only way the conveyer belt needs to start moving in the opposite direction is when the airframe attaches to the wheels moves under the thrust of the propeller.

 

the only way the airframe stays still relative to the air mass it sits in is white powered wheels. When movement of the airframe only exists with thrust from the prop the fact the land it’s standing on is movable is not stopping you accelerating to take off speed.

[Student Pilot]

But what happens if we get an alien invasion while the aircraft is on the conveyor belt? That's just as relevant as the original question.

[facthunter]

The extra information is there to confuse and distract. Use the relevent BASIC forces to decide what will happen and disregard everything else.. Nev

[Student Pilot]

Yeah but what about the aliens?

[kasper]

Yeah but what about the aliens?

Look, we all know that aliens do not need aispeed to fly - they hover and go really fast they they feel fit.

If you like I'll take front row seats and even pay cinema price for pocorn and drinbks if YOU will provide an alien and a rolling runway to test.

= ;-P