Recent content by Joans

Hello. I need some sort of explanation. I was unsuccessfully trying to find information on the web and derivation by hand seems rather complicated for me. So I have a such set-up: HeNe laser ->> plano-concave lense )], light is incident by some angle (NON 0°). then looking to reflection...

I asked the question what should I say to children, F=ma or a=F/m, but almost all replies were that I should adopt different notion of mass and go to the relativistic quantum. I definitely recognize the applicability of theories, it was irony which was hardly noticed. Classical physics is mostly...

That's hardcore... I presume then, that non-relativistic quantum mechanics which I am taught now is rubbish? However it is off-topic. So what about topic? Why does all textbooks and Wikipedia and other sources write rubbish?

How can you describe particle with no mass in theory of relativity or quantum?? I recognize that photon has no rest mass, but It is nonsense, because it does not exists at rest. And then it moves, it have mass from E=mcc... What does it mean to have no mass? What it does not exist?

Which formulation of Newton's second law is more fundamental?? Hi there! I was Googling for interesting demonstrations in Physics, and I was lucky enough to find very interesting blog. Although it is completely new- the guy is writing it only for two weeks, but it already has a lot of nice...

Hello! I am currently a second year student at Scotland (by I am not from UK, I am from smaller country in EU), and I am successfully studying Physics and Maths after successful direct entry to second year. Unfortunately I currently see a big dilemma waiting for me. At first main, general...

I understood, thanks for help!

Yes R is a constant. Okay I guess I understood a bit: x(t) = c_{1}e^{\frac{18(\sqrt{\frac{27}{R^{2}}+\frac{50\sqrt{3}}{9}}-\frac{3\sqrt{3}}{R})}{5\sqrt{3}}t}+c_{2}e^{-\frac{18(\sqrt{\frac{27}{R^{2}}+\frac{50\sqrt{3}}{9}}+\frac{3\sqrt{3}}{R})}{5\sqrt{3}}t} anyway to me it gets too crazy...

Hello, I hope I am writing to right part of a forum... I made a differential equation when I was solving my problem, but unfortunately I am not capable of solving such equation since I am only 12th grader. Or maybe it is not possible to solve it at all...

oR nEWtons 3'rd law?

Hey I have several questions about waves and particles.. I believe I mixing it... Okay firstly we have two stones, One big and one small. First i drop to water one and measure amplitude, freaquency, velocity and energy of a wave. And then another one.. What results I would get, will...

Okay, I figured out it, thanks

How physics works when falling ELASTIC ball hits 45 degree slope? At point of colision what forces are working? As do I believe- in time delta t- one force as moment was straght with y axis(prependicular to ground) and Normal force( or how do u call it) witch is prependicular to 45 degree...

Great, thanks!

I would use calculus if i know how to use it, in school i do not have lessons with it, unfortunately, since I am 11grader. But infact i know quite a lot about it. But still I don't know how to found derirative of the bottom. f(\alpha)=\mu sin(\alpha)+cos(\alpha) f'(\alpha)=\mu...