Physics question - Page 5 - Subaru Enthusiasts Car Club of the Sierras

sperry · 2006-03-11, 01:11 AM

Debbie, the whole point of the question is to realise that an airplane does not push against the gound to accelerate like a car does, it pushes against the air.

dknv · 2006-03-11, 01:13 AM

That's what I meant. The jet engine is the action pushing against the air (the equal & opposite reaction). My previous post was stated very poorly. (See what can happen when you post too quickly!

)

Dean · 2008-01-29, 11:24 PM

Quote:

Originally Posted by http://dsc.discovery.com/tv-schedules/series.html?paid=1.14710.24344.3913.x

Jan 30, 9:00 pm

(60 minutes) MythBusters
Airplane on a Conveyor Belt
TV-PG

In this three-myth blockbuster the team takes a crash-course in remote controlled airplane flying, bug-out by testing the "cockroach survival" theory, then return to fraternity pranks with exploding cans of shaving cream.

That is all...

100_Percent_Juice · 2008-01-30, 12:26 AM

Quote:

Originally Posted by Dean

Please lock this thread and let it die...

...but before the episode airs, I also say no, it will not take off.

AtomicLabMonkey · 2008-01-30, 02:46 AM

I'm tempted to lock this thread preemptively before the arguments start again.

MPREZIV · 2008-01-30, 07:55 AM

Please Austin?

100_Percent_Juice · 2008-01-30, 08:18 AM

better hurry up!

sperry · 2008-01-30, 09:35 AM

I'm going to ban anyone that's dumb enough to believe the conveyor belt can stop a plane from taking off. Anyone with that little grasp on reality should go live in a cave and marvel at the wonder of fire.

cody · 2008-01-30, 09:49 AM

It's a magic conveyor belt though.

*ducks*

Nick Koan · 2008-01-30, 09:50 AM

Quote:

Originally Posted by cody

It's a magic conveyor belt though.

*ducks*

Any sufficiently advanced technology is indistinguishable from magic. Or something like that.

sperry · 2008-01-30, 10:31 AM

Quote:

Originally Posted by sperry

I'm going to ban anyone that's dumb enough to believe the conveyor belt can stop a plane from taking off. Anyone with that little grasp on reality should go live in a cave and marvel at the wonder of fire.

I just re-read my comment.

I'm a huge dick.

...but I stand by my statement.

Kevin M · 2008-01-30, 10:37 AM

Quote:

Originally Posted by sperry

I'm going to ban anyone that's dumb enough to believe the conveyor belt can stop a plane from taking off. Anyone with that little grasp on reality should go live in a cave and marvel at the wonder of fire.

AtomicLabMonkey · 2008-01-30, 11:22 AM

FIRE BAD!

Nick Koan · 2008-01-30, 11:26 AM

But, what about a helicopter on a stairmaster?

knucklesplitter · 2008-01-30, 11:30 AM

Tarzan, Tonto, and Frankenstein say, "Plane no take off!!!11!1"

knucklesplitter · 2008-01-30, 11:33 AM

Quote:

Originally Posted by Nick Koan

But, what about a helicopter on a stairmaster?

If a guy with a rocket pack was on a stairmaster...

knucklesplitter · 2008-01-30, 11:36 AM

If the Earth were spinning at 1040mph surface velocity in the opposite direction of the plane taking off...

Kevin M · 2008-01-30, 11:38 AM

Quote:

Originally Posted by AtomicLabMonkey

FIRE BAD!

That cartoon may have been the single most entertaining thing I've ever seen in my life.

knucklesplitter · 2008-01-30, 11:43 AM

Quote:

Originally Posted by knucklesplitter

Tarzan, Tonto, Frankenstein, and 100% Juice all say, "Plane no take off!!!11!1"

I fixed it for me...

100_Percent_Juice · 2008-01-30, 11:44 AM

Quote:

Originally Posted by Nick Koan

But, what about a helicopter on a stairmaster?

Thats as stupid as the hovercraft on the wave machine.

tysonK · 2008-01-30, 08:21 PM

hell yes.

100_Percent_Juice · 2008-01-30, 08:21 PM

Mythbusters did this...
Find the speed needed for the airplane to take off.
Set the treadmill to that speed in the opposite direction.
Will the airplane take off?

Lets say the take off speed of the airplane is 20mph.
Since the wheels are not powered, it doesn't matter if they are sitting at 0mph or spinning at 100mph, once the prop starts thrust, its going to move the plane forward at the 20mph takeoff speed. Which the airplane took flight in every one of their experiments. I feel this is different then the question that we have been debating. Which I agree the question posted online is flawed.

"Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.
There is no wind.
Can the plane take off?"

This is where the questions differ. Mythbusters set the conveyor for the takeoff speed on the airplane, they did not set the conveyor to match the speed of the wheels at any given time. So of course the plane did not stay in the same place, enabling it to then reach takeoff speed.

IF there was a MAGICAL conveyor that could speed up to infinite MPH and match the wheel mph keeping the airplane in the same place, then the airplane would not take off. That is why the question online is flawed and could never be proven in a real life application because the airplane would match the conveyor speed and add the takeoff speed causing the conveyor to speed up eventually causing the airplane to look like JC's evo.

tysonK · 2008-01-30, 08:26 PM

What the fuck are you doing.

tysonK · 2008-01-30, 08:44 PM

even better

Dean · 2008-01-30, 09:00 PM

How about a bottle rocket in an falling elevator?

Or a hoser not in Canada(The Great White North)?

2006-03-11, 01:11 AM	#101
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	Debbie, the whole point of the question is to realise that an airplane does not push against the gound to accelerate like a car does, it pushes against the air. __________________ Is you is, or is you ain't, my con-stit-u-ints?

2008-01-30, 02:46 AM	#105
AtomicLabMonkey Nightwalker Real Name: Austin Join Date: Dec 2002 Location: Oshkosh, WI Posts: 4,063 Car: '13 WRX YGBSM	I'm tempted to lock this thread preemptively before the arguments start again. __________________ "None of you seem to understand. I'm not locked in here with you.. you're locked in here with me."

2008-01-30, 07:55 AM	#106
MPREZIV Token Real Name: Le Stig Afrique? Join Date: Jun 2005 Location: sitting next to a big yellow box Posts: 3,589 Car: 2001 Impreza 2.5 RS Class: 05 TDSP No, I won't work on your car. F your car*	Please Austin? __________________ "...these condoms have a topical anesthetic to reduce sensitivity, so you can last longer. What a paradox. You can't feel a thing, but you can f*ck for HOURS..."

2008-01-30, 08:18 AM	#107
100_Percent_Juice (40 percent vodka) Real Name: Joel Join Date: Oct 2006 Location: Reno, NV Posts: 4,446 Car: 2004WRX Class: Baby-Hauler/GroceryGetter	better hurry up! __________________ "A power nap is when you sleep on someone who is weaker than you." - Dimitri Martin

2008-01-30, 09:35 AM	#108
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	I'm going to ban anyone that's dumb enough to believe the conveyor belt can stop a plane from taking off. Anyone with that little grasp on reality should go live in a cave and marvel at the wonder of fire. __________________ Is you is, or is you ain't, my con-stit-u-ints?

2006-03-11, 01:13 AM	#102
dknv EJ207 Join Date: Dec 2002 Location: 39n53, 119w90 Posts: 2,698 Car: RX-8 Class: CS maybe	That's what I meant. The jet engine is the action pushing against the air (the equal & opposite reaction). My previous post was stated very poorly. (See what can happen when you post too quickly! )

2008-01-30, 09:49 AM	#109
cody Candy Mountain Real Name: Cody Join Date: May 2005 Location: Californication Posts: 7,751 Car: 03 Pussy Wagon, now with more pink! Class: TESP OMG Internet!	It's a magic conveyor belt though. ducks __________________ Slow and low, that is the tempo.

2008-01-30, 11:22 AM	#113
AtomicLabMonkey Nightwalker Real Name: Austin Join Date: Dec 2002 Location: Oshkosh, WI Posts: 4,063 Car: '13 WRX YGBSM	FIRE BAD! __________________ "None of you seem to understand. I'm not locked in here with you.. you're locked in here with me."

2008-01-30, 11:26 AM	#114
Nick Koan JDM Cowboy Real Name: Nick Join Date: Oct 2003 Location: Somewhere Posts: 8,642 Car: 2015 Mazda 3	But, what about a helicopter on a stairmaster? __________________ While a standard engine is powered by a belt connected to the crankshaft, a turbo engine runs on its own exhaust steam, making it more energy efficient. -- CNN

2008-01-30, 11:30 AM	#115
knucklesplitter EJ205 Real Name: Matt Taylor Join Date: Jun 2005 Location: Cousin-Fck, Carolina Posts: 1,475 Wish in one hand and sht in the other...	Tarzan, Tonto, and Frankenstein say, "Plane no take off!!!11!1"

2008-01-30, 11:36 AM	#117
knucklesplitter EJ205 Real Name: Matt Taylor Join Date: Jun 2005 Location: Cousin-Fck, Carolina Posts: 1,475 Wish in one hand and sht in the other...	If the Earth were spinning at 1040mph surface velocity in the opposite direction of the plane taking off...

2008-01-30, 08:21 PM	#121
tysonK warehouse SECCS Join Date: Mar 2003 Location: SoCal... Posts: 6,253 Car: 04 Evo 99 Cadillac Class: street de le mod	hell yes. Attached Images __________________ Anjali? Anjali?

2008-01-30, 08:21 PM	#122
100_Percent_Juice (40 percent vodka) Real Name: Joel Join Date: Oct 2006 Location: Reno, NV Posts: 4,446 Car: 2004WRX Class: Baby-Hauler/GroceryGetter	Mythbusters did this... Find the speed needed for the airplane to take off. Set the treadmill to that speed in the opposite direction. Will the airplane take off? Lets say the take off speed of the airplane is 20mph. Since the wheels are not powered, it doesn't matter if they are sitting at 0mph or spinning at 100mph, once the prop starts thrust, its going to move the plane forward at the 20mph takeoff speed. Which the airplane took flight in every one of their experiments. I feel this is different then the question that we have been debating. Which I agree the question posted online is flawed. "Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation. There is no wind. Can the plane take off?" This is where the questions differ. Mythbusters set the conveyor for the takeoff speed on the airplane, they did not set the conveyor to match the speed of the wheels at any given time. So of course the plane did not stay in the same place, enabling it to then reach takeoff speed. IF there was a MAGICAL conveyor that could speed up to infinite MPH and match the wheel mph keeping the airplane in the same place, then the airplane would not take off. That is why the question online is flawed and could never be proven in a real life application because the airplane would match the conveyor speed and add the takeoff speed causing the conveyor to speed up eventually causing the airplane to look like JC's evo. __________________ "A power nap is when you sleep on someone who is weaker than you." - Dimitri Martin Last edited by 100_Percent_Juice; 2008-01-30 at 08:23 PM.

2008-01-30, 08:26 PM	#123
tysonK warehouse SECCS Join Date: Mar 2003 Location: SoCal... Posts: 6,253 Car: 04 Evo 99 Cadillac Class: street de le mod	What the fuck are you doing. __________________ Anjali? Anjali?

2008-01-30, 08:44 PM	#124
tysonK warehouse SECCS Join Date: Mar 2003 Location: SoCal... Posts: 6,253 Car: 04 Evo 99 Cadillac Class: street de le mod	even better Attached Images __________________ Anjali? Anjali?

2008-01-30, 09:00 PM	#125
Dean Señor Cheap Bastarde Real Name: Dean Join Date: May 2003 Location: $99 Tire Store Posts: 9,294 Car: $.04 STI Class: Fast,Cheap & Reliable=STI Deal, did somebody say Deal? Oh, Dean, yeah that's me.	How about a bottle rocket in an falling elevator? Or a hoser not in Canada(The Great White North)? __________________ I am a Commodore PET --- Now get off my lawn you kids... Last edited by Dean; 2008-01-30 at 09:41 PM.

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