Recent content by kapitan90

Thanks for your replies!

Yes, but is it incorrect to say that a particle has a definite position and momentum at an instant?

Is that somehow related to limited values of energy an electron can absorb? (I know that it's true when its bounded, but when it escapes its energy stored as kinetic doesn't have to be discrete, right?)

Now I get it, they didn't make that distinction in my textbook. Thanks for your explanation!

Hi, could anyone try to explain one thing about the Heisenberg Uncertainty Principle I don't understand? The principle says is impossible to measure the position and momentum of a small particle with absolute accuracy. But this doesn't mean the particle doesn't have a definite position and...

Hello, I have a problem with the two seemingly conflicting descriptions of the energy transfer from a photon to an electron I found in my textbook. The first one appears in the description of the photoelectric effect: "In Einstein's picture, an individual photon arriving at the surface...

Homework Statement Hello, I have a question concerning convergence of the non-monotonic sequences which takes place when the Cauchy criterion is satisfied. I understand that |a_n - a_m| <ε for all n,mN\ni Homework Equations What I don't see is how (a_{n+1} - a_n) →0is not...

Could anyone explain why the electromagnetic effects need to be considered and how it influences the ratio?

Could anyone please have a look at this problem? I thought it was quite straightforward :(

Homework Statement I was supposed to use dimensional analysis to approximate the length scale (in classical and quantum mechanics). The results I got(same as those in the answer sheet): classicalyl_c≈\frac{e^2}{4πm_ec^2ε_0}≈2.8*10^-15m In quantum mechanicsl_q≈\frac{h}{m_ec}≈2.4*10^-12m...

Homework Statement Hello, I have problems with expressing a reflected wave mathematically. In my printed notes I found the following formulas for reflected waves: a) For a fixed end: incoming wave: y_1(x,t)=e^{-i(kx+ωt)} reflected wave: y_2(x,t)=re^{i(kx-ωt)} where r is the reflection...

Thanks for your reply. I understood the first problem, but I still have problems with the second one. These are the coordinates of an object in a frame S', moving with velocity u with respect to S, in which the object is in rest: x_1'=γ(x_1-ut) x_2'=γ(x_2-ut) Then Δx'=γΔx so the object appears...

Homework Statement Hello, I have a question about length contraction transformation. In my textbook it looks like this: x_1=γ(x_1'+ut'), x_2=γ(x_2'+ut') If the coordinates of the two events are (x_1,t_1), (x_2, t_2) , why is t used instead of t_1and t_2? The second problem I have is with...

I am also supposed to show that the kinetic energy of a particle accelerated from rest to v_x isW =∫F_xdx=m_0c^2(γ-1) but I am stuck with the integral∫ (1-v^2/c^2)^{-0.5} dx I tried to integrate it by parts and to use Wolfram, but it couldn't solve it either. Any ideas?

Homework Statement I am supposed to show that the force on a relativistic particle when a) it's perpendicular to particle's velocity is F=γm_0\frac{dv}{dt} b) it's parallel to particle's velocity is F_x=m_0γ^3\frac{dv_x}{dt} I may make use of the fact that...