I call bullshit. That site claims that the real answer is 1.34 x 10^-6 nm.

Is that MathXL or some variant?

Something like that, yes. Online homework that the professor assigns en masse because he is too shitty of a teacher to actually teach.

And he he he talks like like um like this during lectures. Quite naturally, listening to the lecture is about as educational as watching a brick wall weather in the elements.

Oh. If it was MathXL, I'd tell you to go back to the practice problems, find one like it and choose the "show me" option, it used to help me.

I got 1.34e-6 nm

Relativistic effects. At 2.96 x 10⁸ m/s, the sqrt(1 - v²/c²) factor in the equation can no longer be approximated as 1.

"Estimate" the wavelength. So approximate everything, lolololol.

If only I can approximate away loan interest rates like that, Vrael >_>.

EDIT> Here, try out these two questions:


Tell me what you get. If you are not stupid, your answers will be the same as what I obtained, however, the system will rule them as incorrect.



Post has been edited 3 time(s), last time on Sep 24 2011, 1:11 am by Aristocrat.

Quote from Aristocrat

Collapsable Box

11500 meters and 1.4 degrees Fahrenheit, correct? Wrong!

According to the system, you are supposed to get 722 meters and 1 degree Fahrenheit exactly.

The degrees I could argue that they rounded to the nearest whole degree, even though that would ignore significant figures, but the first question is so bizarrely "off" that I can't even tell what they did. They did give the measurements in Imperial units for the copper wire and are asking for SI units, so I'd assume, especially since the "correct" answer is considerably less than yours (which I will assume is right, I only went through part of the problem at this point), the error lies in them not converting to SI units.

EDIT: Though looking at the problem again, you're both saying just a few kg of Cu can be stretched out to 3/4 of a km, or just over a km. At that point, it just becomes asinine to split hairs; it's a good fucking stretch imo.

I agree.. it is significantly wrong to take ɣ=1 when the velocity is about 0.986 c. Exactly, I got 2.122 x 10^-7 nm