Physics Question for you.....

[BobSch]

Wrong question, we will send some mice over to make sure you get it correct.

Have a few more pan galactic gargle blaster until they arrive.

And thanks for the fish.

[TheRic]

Wow... and I always thought the answer was 42. Time for another pan galactic gargle blaster, I guess....

Wrong question, we will send some mice over to make sure you get it correct.

Have a few more pan galactic gargle blaster until they arrive.

[Alex Franke]

Wow... and I always thought the answer was 42. Time for another pan galactic gargle blaster, I guess....

[TheRic]

..I can't believe this topic has gone 13 pages.

They did say it was the #1 fan requested thing... or something like that.

Even the pilot (used in this test result) thought it would sit there. SO I can see why many people are 100% sure their theory is correct.

[Russianwolf]

I don't think the wheels will be doing 200 mph. If it were a car and being driven by the wheels. If the wheels didn't spin (0 mph) the plane would move 100 mph in reverse -- but since the plane is stationary they'll be moving at 100mph. If the plane moves forward at 1 mph then the wheels would be spiing at 101 mph..

The 100 mph needed for takeoff in the above example would be the plane's body in relation to the ground. Not in relation to the conveyor surface. So the wheel would indeed spin at an rpm equivalent to twice the speed of the body to the ground (200 mph in the example).

Or as you said. The plane is moving forward at 100 mph, so the wheels would be spinning at 200mph.

I can't believe this topic has gone 13 pages.

[guycox]

Yes, the plane uses air to push, not friction with the ground. Let's say it needs a speed of 100 to take off. At the moment of takeoff it is moving 100. The converyor is moving at 100 backwards. The wheels are effectively spinning at 200. Assuming the wheels can handle double speed without blowing out, should be able to take off.

I don't think the wheels will be doing 200 mph. If it were a car and being driven by the wheels. If the wheels didn't spin (0 mph) the plane would move 100 mph in reverse -- but since the plane is stationary they'll be moving at 100mph. If the plane moves forward at 1 mph then the wheels would be spiing at 101 mph..

[Mr__Bill]

Yes, the plane uses air to push, not friction with the ground. Let's say it needs a speed of 100 to take off. At the moment of takeoff it is moving 100. The converyor is moving at 100 backwards. The wheels are effectively spinning at 200. Assuming the wheels can handle double speed without blowing out, should be able to take off.

The fact that the runway moves is irrelevant. Offthemark has it right!

oops, somehow I missed that there were a gazillin replies to this, but the plane sill takes off

[BigguyZ]

I was going to find this thread too and mention the Mythbusters episode. Too bad you beat me to it. I found it funny that the very pilot they hired to do the test thought the plane would "sit there like a brick".

[TheRic]

Mythbuster test

Mythbuster did the plane on a conveyor belt test tonight.

They even explained why in the "Science Content" section.

The found that on the small scale and the full size scale........

.

.

.

.

.

.

.

.

.

.

.

.

the plane took off.

I guess this resolves this question that has been plaguing mankind.

[crokett]

Too lazy to read 13 pages and see if I replied before so....


If I answered no previously, changing my answer to yes. I thought of an example that works that we can relate to.

Take your belt sander and flip it upside down. Turn it on. Take your kid's R/C car and fire that sucker up. Put it on the belt sander and pretend for a minute that the belt sander RPMs match the wheels. The car will stay in place on the belt sander.

Now doctor the car so the wheels are disconnected from the motor and spin freely. Strap a model rocket engine to the roof - this is the same as a jet. Turn on the belt sander. Drop the car on the belt sander and hold it in place while you ignite the egine. Let it go and the car will go flying across your shop. The thrust from the engine is not against the belt sander, rather the hot gases shooting out of the engine are pushing it. It doesn;t give a hoot that the ground is moving under it.

[Stytooner]

No stipulations as to a number.
If it was a sharp plane, I think it would take off and fly, unless I was using it. In this case it would sit and rust.

I do have one that actually moves though. Typical block plane. This would create belt movement, but after a couple inches, I'd give out and grab a file. How far will a file fly?

[TheRic]

Okay, this is a scenario I haven't seen. What if it's a Stanley plane?

Number 5 or Number 8??!

Okay, this is a scenario I haven't seen. What if it's a Stanley plane?

Then it will dig into the conveyor and get lost in the rollers!

[Stytooner]

Okay, this is a scenario I haven't seen. What if it's a Stanley plane?

Oh forgedaboutit!

The plane will crash!!!!!!!!!!!!!!!!!!!!!!!!!!