calling high iq'es

hascoolnickname · Post by **hascoolnickname** » Sat Jan 07, 2006 11:50 pm

dont deny it, you would
<<<this dog is vrooming away too

Potter · Post by **Potter** » Sun Jan 08, 2006 12:10 am

GREAT SCOTT WHERE IS ALL HIS THRUST GOING!!!!?!

Gumby · Post by **Gumby** » Mon Jan 09, 2006 2:37 pm

I haven't really read this entire thread because I'm impatient. The answer to the question is as such.

what would happen in this situation, if the "treadmill" can automatically match the speed of the wheels in the opposite direction, the wheels would end up rotating infinitely fast for the plane to move forward. In fact, for the plane to be moving forward, and assuming the wheels don't slip on the surface of the treadmill, they would have to be spinning faster than the treadmill which we surmised won't happen because the treadmill automattically matches their speed.

The key to this whole problem is friction. The wheels of a plane are free rolling. If there were no friction, then free rolling wheels of a plane on a treadmill would just spin at the speed of the treadmill and the plane would stay stationary. It is because of friction that if you set a wheeled object on a moving surface that it will move in the direction of that surface.

If we consider the problem without friction, then the thrust of a jet engine would compel the jet to move forward. However, if we also assume that the surfaces of the wheels and treadmill will not slip past each other, then the jet could not possibly be moving forward and still have the condition that the wheels and treadmill are matching speeds. That's a simple impossibility with the given assumptions. The wheels and treadmill would constantly be counteracting each other and accelerate to infinity but the wheels would have to be spinning at infinity plus some for the jet to move forward relative to the earth.

Let's entertain the real world situation...

If you take friction into account (which does exist in the real world) the wheels would rotate to a point that the bearings heat to melting, they would seize, and the jet would suddenly fly backwards off the treadmill like the funny video of the idiot falling face first onto the speeding treadmill.

This is my input into the problem and well... I'm a damn genius so I must be right. I commend you Potter on posting quite an intriguing brain teazer. Quite possibly the most useful post you have ever made.

Gumby · Post by **Gumby** » Mon Jan 09, 2006 3:15 pm

well damn i should have read the whole thread. Given potter's miswording of the original post, then Dragon's answer is correct. The plane can take off and the wheels would be spinning twice as fast as they would if the plane were taking off on normal ground.

Gumby · Post by **Gumby** » Mon Jan 09, 2006 3:17 pm

thinking about it now, I think the question is much more fun if the treadmill were supposed to match the speed of the wheels. In which case my original answer was correct.

Triple post FTW

hascoolnickname · Post by **hascoolnickname** » Mon Jan 09, 2006 4:06 pm

lol
welcome back dude

roxygurl · Post by **roxygurl** » Mon Jan 09, 2006 8:22 pm

planes=scary.... treadmill or not

Green Tea · Post by **Green Tea** » Mon Jan 09, 2006 8:35 pm

Gumby wrote:well damn i should have read the whole thread. Given potter's miswording of the original post, then Dragon's answer is correct. The plane can take off and the wheels would be spinning twice as fast as they would if the plane were taking off on normal ground.

like you, I didn't feel like reading through everything, but just a random addition, the plane can only take off if there are three things.

1. The overall net movement of the plane is forwards.
2. There is air resistance.
3. Riot is present.

The third is optional, but recommended. If Riot is not there, then he might be angered and destroy it.

Gumby · Post by **Gumby** » Tue Jan 10, 2006 9:45 am

Here's another fun physics brain buster. This one isn't quite as difficult as the jet treadmill one but it's fun nonetheless.

Consider a large open container of water with a boat floating in it. In the boat is a man and a pile of rocks. The man starts to throw the rocks overboard and they sink to the bottom of the container. As he progresses through this exercise, will the level of the water relative to the container...
a) go up
b) go down
c) stay the same

First one to answer correctly (and justify why the answer is correct) will win five internets.

sam · Post by **sam** » Tue Jan 10, 2006 10:17 am

same...the laws of bouyancy are AMAZING

also about the friction...it is only resistance to thrust. the actual speed of what you're doing on the ground is irrelevant. It's just coincidence that jet airplanes get enough thrust at 180MPH to take off. With this model the plane would be moving twice as fast to get the thrust to take off since there's no friction.

Mosh_Mosh_Revolution · Tue Jan 10, 2006 1:14 pm

Lololololol, three pages about if a plane can fly or not under specified conditions.

...I guess this is where I get to be a stereotypical girl: not really get it, shrug, and go back to whatever I was doing before.

Potter · Post by **Potter** » Tue Jan 10, 2006 4:07 pm

Gumby wrote:Here's another fun physics brain buster. This one isn't quite as difficult as the jet treadmill one but it's fun nonetheless.

Consider a large open container of water with a boat floating in it. In the boat is a man and a pile of rocks. The man starts to throw the rocks overboard and they sink to the bottom of the container. As he progresses through this exercise, will the level of the water relative to the container...
a) go up
b) go down
c) stay the same

First one to answer correctly (and justify why the answer is correct) will win five internets.

what do you mean by level of water?

the water will rise slightly because of its displacement, but the amount of water stays the same.

hascoolnickname · Post by **hascoolnickname** » Tue Jan 10, 2006 4:40 pm

Potter wrote:
Gumby wrote:Here's another fun physics brain buster. This one isn't quite as difficult as the jet treadmill one but it's fun nonetheless.

Consider a large open container of water with a boat floating in it. In the boat is a man and a pile of rocks. The man starts to throw the rocks overboard and they sink to the bottom of the container. As he progresses through this exercise, will the level of the water relative to the container...
a) go up
b) go down
c) stay the same

First one to answer correctly (and justify why the answer is correct) will win five internets.
what do you mean by level of water?

the water will rise slightly because of its displacement, but the amount of water stays the same.

Wouldn't it stay the same because the amount of water that is displaced from the boat? If you throw the rock over the weight of the rock is gone from the boat, and the boat rises a little- when the rock goes in the water the water rises a little; so no net change?

Potter · Post by **Potter** » Tue Jan 10, 2006 4:43 pm

not really if the boat we are talking about is a treal size one and he is throwing your garden variety size rocks. or maybe im wrong i have nbo c,lue im jst pissed my rear shock is due for a rebuild

sam · Post by **sam** » Tue Jan 10, 2006 5:40 pm

water is displaced by mass. When you put something in water the voulme will changed based on the mass. When you put it on water the volume will change based on the mass. Mass does not change so the water displacement will be the same.