Physics question - Page 4 - Subaru Enthusiasts Car Club of the Sierras

cody · 2005-11-28, 08:24 PM

It might have somthing to do with number of members each forum has...

Nick Koan · 2005-11-28, 08:26 PM

Quote:

Originally Posted by JC

Ya well half of us are engineers and one of us is an airplane designer.

and one of us is an engineer who is extremely bad at physics.

/tries not to look at self in mirror

Kevin M · 2005-11-28, 09:03 PM

Quote:

Originally Posted by BAN SUVS

Okay now I get it. The conditions of the question cannot be met with an aircraft.

Do I get a cookie for saying this first? (As far as I know; I only read the first page of the nabisco thread)

Ezdno · 2005-11-28, 11:45 PM

What kind of cookie would you prefer?

M3n2c3 · 2005-11-29, 07:40 AM

Quote:

Originally Posted by cody

It might have somthing to do with number of members each forum has...

Does someone want to figure out the ratio of registered members to pages or posts in the respective threads?

Quote:

Originally Posted by JC

Ya well half of us are engineers and one of us is an airplane designer.

I am most certainly not an engineer, hence my absence from the technical parts of the discussion

MPREZIV · 2005-11-29, 07:47 AM

makes sense to me: plane not moving, air not flowing over wings, no lift, no flight.

the tires could be going as fast as you could imagine, and with no air over the wings for lift, the thing won't leave the ground.

(scratches head)

M3n2c3 · 2005-11-29, 08:12 AM

Quote:

Originally Posted by MPREZIV

makes sense to me: plane not moving, air not flowing over wings, no lift, no flight.

the tires could be going as fast as you could imagine, and with no air over the wings for lift, the thing won't leave the ground.

(scratches head)

I think the general idea that our aerospace engineers here are trying to get at is that there's really no way a conveyor belt could stop a plane from moving, since a plane uses thrust from the turbines to move, not rotation of the wheels. The real confusion is coming from the poor wording of the problem. The idea is improbable in the first place.

Now, if a Subaru was on a conveyor belt. . .

doubleurx · 2005-11-29, 09:47 AM

Me for the win - post #6.

sybir · 2006-01-21, 10:45 PM

Here we go again

http://www.i-club.com/forums/showthread.php?t=124084

Blame Ed

doubleurx · 2006-01-23, 09:28 AM

Oh my god. People cannot think! I couldn't get past the second page.

Ouch!

A1337STI · 2006-03-08, 10:57 AM

lamo air speed =0 of the needed 150. no take off. period.

easy one (course i've taken hang gliding lessons)

assume the needed Air wing speed for take off is 150 .

the aircraft engine sends thrust backwards , this pushes the air plane forwards.
as the plane starts to move forward (1 mph) the weight of the plane still bares down on the tires, the friction between the conveyor belt and the tires is great or than the friction of the wheel bearing (assuming no brakes are applied) the wheel rotates . the rotation of the wheel triggers the conveyor belt to move backwards at 1mph. thrust is still applied so the plane again moves forward and repeat.

with a jet engine there is not a great deal of air flow Over the wings by the jet engine alone, wings produce no lift . you've just created a very Inificient fan.

If its a propeller in front of the wings you will have air flow over the wings and create lift and you will take off with a ground speed of zero if you can manage to get the air moving fast enough around your wings.
so it should depend on engine placement.

also by exact definition of the question. if you locked your tires up, and the trust of your engine was enough to overcome the friction of the tires(lockedup) you'de slide them (not rotate) and the convyer belt wouldn't start up...

(please at least post back the correct answer for the thread is locked )

Dean · 2006-03-08, 11:00 AM

Please lock this thread and let it die...

JonnydaJibba · 2006-03-08, 11:15 AM

Nick Koan · 2006-03-08, 11:19 AM

Quote:

Originally Posted by Dean

Please lock this thread and let it die...

I'm almost tempted to lock all the old threads now...

JC · 2006-03-08, 11:20 AM

Quote:

Originally Posted by A1337STI

(please at least post back the correct answer for the thread is locked )

Quote:

Originally Posted by JC

No, I'm an aerospace engineer. I should know.

Quote:

Originally Posted by JC

If your wheels are moving at the same speed as the treadmill, apply a no slip condition then the plane isn't moving regardless of how you are applying thrust. If the plane doesn't move, you don't take off.

FTW

cody · 2006-03-08, 11:23 AM

Loud Noises!!!

Evo Mike · 2006-03-08, 12:20 PM

it shouldn't be able to take off.... i hated physics by the way.

MPREZIV · 2006-03-08, 12:22 PM

Why are we on this again?

i just got a nose bleed...

sperry · 2006-03-08, 12:30 PM

HOLY JESUS PEOPLE.

As originally written the question has no solution, there is a logical block in the wording.

As it should have been written, the plane will take off, with a wheel speed twice that of the airspeed.

Please read the thread before restarting this nightmare of an argument.

JonnydaJibba · 2006-03-08, 12:36 PM

I don't know why we're yelling!

cody · 2006-03-08, 01:13 PM

JC · 2006-03-08, 01:29 PM

Quote:

Originally Posted by JonnydaJibba

I don't know why we're yelling!

We can't hear each other over the rod knock from your car!

A1337STI · 2006-03-09, 04:11 PM

my bad. lets lock the search button ...

JonnydaJibba · 2006-03-10, 08:43 AM

Quote:

Originally Posted by JC

We can't hear each other over the rod knock from your car!

Ooooh. You cut me deep on that one.

dknv · 2006-03-10, 11:56 PM

I was gone somewhere when this discussion was taking place. Otherwise, I would've put my simplistic answer as such

For every action there is an equal and opposite reaction.

Since an airplane, by our typical definition of terms, is assuming the reaction is a stable ground, no, the plane will not take off on a conveyor belt.

--> this person has never taken physics, but remembers stupid memory joggers.

T'was a good discussion all over the place anyway.

2005-11-28, 08:24 PM	#76
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 might have somthing to do with number of members each forum has... __________________ Slow and low, that is the tempo.

2005-11-28, 11:45 PM	#79
Ezdno EJ251 Real Name: Dean W. Join Date: Nov 2005 Location: So close to hell you can see Sparks! Posts: 541 Car: 1992 F250 1T Monster Class: none They were all dead when I got here!	What kind of cookie would you prefer? __________________ Don't interupt me while I am ignoring you!

2005-11-29, 07:47 AM	#81
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*	makes sense to me: plane not moving, air not flowing over wings, no lift, no flight. the tires could be going as fast as you could imagine, and with no air over the wings for lift, the thing won't leave the ground. (scratches head) __________________ "...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..."

2006-01-21, 10:45 PM	#84
sybir The Don Real Name: Aaron Join Date: Oct 2003 Location: Sacramento Posts: 3,097 Car: '97 Legacy / '05 FXT Class: low	Here we go again http://www.i-club.com/forums/showthread.php?t=124084 Blame Ed __________________ Tact is for people who aren't witty enough to be sarcastic.

2006-03-08, 10:57 AM	#86
A1337STI EJ205 Join Date: Jan 2006 Location: Reno, NV Posts: 1,840 Car: Impreza and an Impreza Class: AS / CRS PerfStock "pedal on the right"	lamo air speed =0 of the needed 150. no take off. period. easy one (course i've taken hang gliding lessons) assume the needed Air wing speed for take off is 150 . the aircraft engine sends thrust backwards , this pushes the air plane forwards. as the plane starts to move forward (1 mph) the weight of the plane still bares down on the tires, the friction between the conveyor belt and the tires is great or than the friction of the wheel bearing (assuming no brakes are applied) the wheel rotates . the rotation of the wheel triggers the conveyor belt to move backwards at 1mph. thrust is still applied so the plane again moves forward and repeat. with a jet engine there is not a great deal of air flow Over the wings by the jet engine alone, wings produce no lift . you've just created a very Inificient fan. If its a propeller in front of the wings you will have air flow over the wings and create lift and you will take off with a ground speed of zero if you can manage to get the air moving fast enough around your wings. so it should depend on engine placement. also by exact definition of the question. if you locked your tires up, and the trust of your engine was enough to overcome the friction of the tires(lockedup) you'de slide them (not rotate) and the convyer belt wouldn't start up... (please at least post back the correct answer for the thread is locked ) Last edited by A1337STI; 2006-03-08 at 11:14 AM.

2005-11-29, 09:47 AM	#83
doubleurx EJ205 Join Date: May 2004 Location: Truckee Posts: 1,948	Me for the win - post #6.

2006-01-23, 09:28 AM	#85
doubleurx EJ205 Join Date: May 2004 Location: Truckee Posts: 1,948	Oh my god. People cannot think! I couldn't get past the second page. Ouch!

2006-03-08, 11:00 AM	#87
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.	Please lock this thread and let it die... __________________ I am a Commodore PET --- Now get off my lawn you kids...

2006-03-08, 11:15 AM	#88
JonnydaJibba EJ207 Join Date: Apr 2005 Location: Reno/Sparks, Nevada Posts: 3,482 Car: 2000 2.5RS Class: RestNPeace Master Slurper.	__________________ "Why do chicks tell you to call and then not answer....so gay." "Cuz girls are fags I dunno"

2006-03-08, 11:23 AM	#91
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!	Loud Noises!!!

2006-03-08, 12:20 PM	#92
Evo Mike EJ251 Join Date: Apr 2004 Posts: 513	it shouldn't be able to take off.... i hated physics by the way. __________________ I Can't Believe My Friends.... Drive WRX's....

2006-03-08, 12:22 PM	#93
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*	Why are we on this again? i just got a nose bleed... __________________ "...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..."

2006-03-08, 12:30 PM	#94
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	HOLY JESUS PEOPLE. As originally written the question has no solution, there is a logical block in the wording. As it should have been written, the plane will take off, with a wheel speed twice that of the airspeed. Please read the thread before restarting this nightmare of an argument. __________________ Is you is, or is you ain't, my con-stit-u-ints?

2006-03-08, 12:36 PM	#95
JonnydaJibba EJ207 Join Date: Apr 2005 Location: Reno/Sparks, Nevada Posts: 3,482 Car: 2000 2.5RS Class: RestNPeace Master Slurper.	I don't know why we're yelling! __________________ "Why do chicks tell you to call and then not answer....so gay." "Cuz girls are fags I dunno"

2006-03-08, 01:13 PM	#96
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!

2006-03-09, 04:11 PM	#98
A1337STI EJ205 Join Date: Jan 2006 Location: Reno, NV Posts: 1,840 Car: Impreza and an Impreza Class: AS / CRS PerfStock "pedal on the right"	my bad. lets lock the search button ...

2006-03-10, 11:56 PM	#100
dknv EJ207 Join Date: Dec 2002 Location: 39n53, 119w90 Posts: 2,698 Car: RX-8 Class: CS maybe	I was gone somewhere when this discussion was taking place. Otherwise, I would've put my simplistic answer as such For every action there is an equal and opposite reaction. Since an airplane, by our typical definition of terms, is assuming the reaction is a stable ground, no, the plane will not take off on a conveyor belt. --> this person has never taken physics, but remembers stupid memory joggers. T'was a good discussion all over the place anyway.

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