The "Plane on a Treadmill" Question

[Flint]

Originally Posted by glatt

What has Occam's Razor got to do with this situation?

Not making unwarranted assumptions or adding extra information.

The question does not define "forward speed" in a way that makes the question answerable, and you can't make it so, without going outside of what is stated. (See: most of this thread.) Step #1, often overlooked, is to read the question and establish what is being discussed. In this case, you can't - the question does not contain the information. Any attempt to re-write the question means you are not answering the original question.

[hideouse]

I owe you an apology. You did note the flaw in the original premise and i missed it. Please excuse me.

[xoxoxoBruce]

The question states the plane moves forward and the ground(treadmill)moves backwards. When you throttle up the plane will take off. The only assumption is the plane is capable of flying in the first place.

[Flint]

"moves forward"

Relative to what? Not stated.

[glatt]

Originally Posted by Flint

Relative to what? Not stated.

Relative to the same observer who sees the treadmill moving. If the observer sees the treadmill moving, he isn't on it.

[Flint]

Originally Posted by glatt

Relative to the same observer who sees the treadmill moving.

This isn't a first person account of an actual event, it's a hypothetical. It could just as likely be written from an omniscient perspective, as the events described are not actual events. The question doesn't make this distinction, so you can't. If you re-write the question, you're no longer answering the question.

[glatt]

You mentioned Occam's razor before. Is it simpler to have one point of view of both the plane and treadmill, or is it simpler to have a point of view that is jumping all over the place?

Consider that the one point of view keeps the question clear, and the multiple points of view or omniscient point of view muddies the meaning of the question.

How does Occam's Razor apply here?

[xoxoxoBruce]

Originally Posted by Flint

Relative to what? Not stated.

If it's not stated, then it's relative to where it was and nothing else.

[Flint]

"forward speed"

Originally Posted by Flint

Relative to what? Not stated.

Originally Posted by xoxoxoBruce

If it's not stated, then it's relative to where it was and nothing else.

The surface it's on, or the surface next to the surface it's on? Not stated.

[xoxoxoBruce]

No, if it's not stated you can't chose what to relate it to, that's adding to the question. It can only be relative to where it was if it moved, which the question states it did.

[tw]

Originally Posted by Flint

The question does not define "forward speed" in a way that makes the question answerable, ...

Of course it does.

When the plane's engines throttle up, it begins to move forward,

The classic F=ma relationship and the classic v=ma . Foreward speed is defined once we have numbers for these simple equations. And again, treadmill and observer will only confuse one with irrelevant parameters.

[Torrere]

Originally Posted by tw

Of course it does. The classic F=ma relationship and the classic v=ma .

the classic v = ma? I'm not familiar with that one. Are you confusing yourself with v=at or p=mv?

Originally Posted by tw

Just because they did not tell you which to use as the reference point, then you cannot arbitrarily choose one? Nonsense. See the previous post. Choose air as the reference point.

The problem is not explicit, therefore you must do whatever tw tells you to do.

[Flint]

Originally Posted by Flint

Any attempt to re-write the question means you are not answering the original question.