# Recent content by IWantToLearn

1. ### A Change of ε with pressure for Semiconductors

In "Sado Adachi" book "Properties of Group-IV, III–V and II–VI Semiconductors" page 222, he reported that "both εs and ε∞ decrease almost linearly with increasing pressure", however i was not able to find any empirical formula to describe these relationship for materials InAs, InP, InSb, where...

Thanks :)
3. ### Revisiting Newton's Second Law

I wonder why newton second law, define force as mass x acceleration, acceleration is the second time derivative of displacement, why he didn't define the force as mass x higher order time derivatives of displacement
4. ### I From Non Hermitian to Hermitian Matrix

Is there any way that i can convert a non-hermitian matrix to a hermitian matrix ?
5. ### I Spiral Equation

thank you for your interest in the question, i was not quite clear in stating the problem, by family of curves i mean a family curves that all intersect at one single point, and they are identical such that you can have them all by rotating one of them around an axis at the point of...
6. ### I Spiral Equation

I am looking for a family of curves where if we consider one curve of them and get the tangent of that curve at any arbitrary point on the curve, then you will always find a point in the other curves where the tangent of this point is perpendicular to the tangent of the first point. My guess...
7. ### I Great Circle Distance Derivation

I want to convince myself that this formula (ds)2= R2 [ (dθ)2 + sin2θ (dφ)2 ] is true
8. ### I Great Circle Distance Derivation

I derived the shortest distance between two points on a spherical surface (Great Circle Distance) , using the definition of the spherical coordinates and the dot product of the position vectors r1 and r2 where r1 = ( R cosθ1 cosφ1 , R cosθ1 sinφ1 , R sinθ1 ) r2 = ( R cosθ2 cosφ2 , R cosθ2 sinφ2...
9. ### Relativistic Calculations for De-Broglie Wavelength

As far as i understand, there is nothing in the first approach states that the De-Broglie wavelength depend in anything but the momentum in the first approach i replaced the momentum by the kinetic energy, and this is a valid replacement please explain your point
10. ### Relativistic Calculations for De-Broglie Wavelength

Homework Statement At what energy will a non-relativistic calculation of the De Broglie wavelength of an electron be in error by 5%? What is this energy for a proton? Comment on your results. Homework Equations I have two (seemed to be) logical answers for this question, but with different...
11. ### Conditions in Wave Function, and Integration

I want to know how this integral will equal zero? I know that Ψ will fall to zero as x goes to infinity and i know that Ψ must fall to zero very quickly , Ψ must fall to zero faster than 1/√|x| all of this will help evaluating this integral i tried to solve it as follows The first term...
12. ### Transformers and iron cores and frequency

What about the frequency of the secondary voltage? it will increase?
13. ### Transformers and iron cores and frequency

As far as i understand the thing that matter in all of the process of mutual inductance is the rate of change of the current in the primary coil $$\frac{dI}{dt}$$ butting soft iron core will increase the density of the magnetic field inside the primary coil, but how this will effect...
14. ### Relaxation time approximation and ideal hydrodynamics

unfortunetly there is nothing more
15. ### Relaxation time approximation and ideal hydrodynamics

Homework Statement please check attachment Homework Equations please check attachment The Attempt at a Solution since the deviation from f_0 to f is linear then we can write f=f_0 + C where C is some constant this should be enough to prove the first question (i think so) for the second...