Recent content by cantgetaname

Found solution here:http://math.stackexchange.com/questions/855255/prove-maximum-term-in-the-expansion

Homework Statement So I want to prove that the expression 20Cr×0.1r 0.9(20-r) reaches maximum value for r=(0.1)×20=2 Homework EquationsThe Attempt at a Solution I can prove it by trial and error but can't differentiate the expression because nCr isn't continuous.

That book does answer my question (although at present a lot of it goes over my head). Thanks!

I'm trying to understand how the Navier-Stokes equations are derived and having trouble understanding how the strain rates are related to shear stresses in three dimensions, what a lot of texts refer to as the 'Stokes relations'...

I've been trying to understand the major systems for hours. All are ridiculously complicated and seem to make no sense. Wikipedia articles are poorly written and google is having a hard time digging something useful. If any of you guys have any links that do a good job of explaining any system...

I was walking home today when I noticed that the flash from a lighting takes a fraction of a second while the sound lasts a good 5-6 seconds. I couldn't think of an explanation for this, except a wild guess that maybe the source of sound is a line source and sound from different points on the...

Assuming you meant how bond length data is obtained experimentally, it is done by spectroscopic methods. One of probably many such techniques... http://en.wikipedia.org/wiki/X-ray_crystallography

Why is something like Fluorine written as 1s^{2}\;\;2s^{2}\;\;2p_{x}^{2}\;\;2p_{y}^{2}\;\;2p_{z}^{1} and not 1s^{2}\;\;2s^{2}\;\;2p_{x}^{2}\;\;2p_{y}^{1}\;\;2p_{z}^{2}? 2p_{y}^{1} and 2p_{z}^{1} should be of the same energy, right? Or is it only a matter of convenience/convention which one...

Thanks for clearing that. As I said, I have successfully solved the problem before using the method you just suggested. I was also aware of the requirement of one axis throughout the problem, but I neglected/couldn't figure out in a hundred years that any translational motion would also...

Homework Statement The figure shows two cylinders of radius r1 and r2 rotating about their axes (along the length) with speeds \omega_1 and \omega_2 The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of...

Anyone?

The mistake you've made is 'I=ma^2' which is only valid for a point particle. The ride could be any complex shape you can't say anything about. So moment of inertia after 4 men go on is: 1750 + 4*(65)*((4.5/2)^2) the men are assumed to be point masses at a distance a/2 so their moments...

Homework Statement The figure shows two cylinders rotating about their axes, all the variables involved are shown. The two cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the point of contact but slipping finally ceases due...

Thanks for your reply. So if I'm not wrong, along the new axis the angular momentum will be the same as the one in the middle? (in this case)

Hmmm... I'll do it. No shortcuts? I wanted to know this so that certain problems would be faster to solve.