Focusing sound waves
Is there any way to focus a sound wave BEHIND an acoustic lens i.e. the source and receiver are on different sides of the lens? Will it result in a significant loss of sound energy?
View ArticleIntensity for circular polarised light through linear polariser
Hi, does the intensity change when circularly polarised light passes through a linear polariser? I am thinking of a flow like this: natural light -> vertical linear polariser -> quarter wave...
View ArticleWill an infinite plane of charge flux generate flux through itself?
I just have a quick question, and I'm guessing the answer is no but I wanted to make sure that this was sensible. In general whenever we consider flux we think of some kind of closed surface or a...
View ArticleEddy current calculations
Hi all i hope some one can help but i have a feeling there will be no easy calculations for this one:confused: Im trying to calculate actual eddy current losses in 50hz mains transformers depending on...
View ArticleOverall Intensity of Destructively Interfering Waves
If you have two sound sources emitting the same frequency and in phase with each other such that the emitted waves destructively interfere along the line containing the two sources, is the intensity at...
View ArticleUsing Gauss's Law to find E for an infinite volume charge density
My E&M professor brought up this problem of considering a uniform charge density, rho, that is infinite in volume and then using Gauss's Law to find the electric field at a point. It's resulted in...
View ArticleEq. of motion of elastic 2D finite element
A simple question about elasticity theory/finite element method: Suppose I have a tetragonal 2D piece of a linear isotropic elastic material, that has Young's modulus ##E## and Poisson's ratio ##\nu##....
View ArticleElectric field in a solenoid/inductor.
Hello, I am trying to create a decent magnetic field in an inductor, I come from an electronics background so I am not a master physicist (I might use this knowledge later if I build an radio system or...
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What the destructive force of the shock wave depends on?
When the powerful (nuclear) bomb explodes it generates the shock wave that destroys everything around it. I want to know, does the force of this shock wave depend on the air pressure and density?...
View ArticleAtwood's Machine
Atwood's Machine, with one pulley and two weights, is analyzed with two free body diagrams. Each diagram depicts the forces applied to each weight. If the weights are connected, why isn't gravity...
View ArticleStationary object, constant velocity?
I had an interesting debate with a friend of mine recently. They claim that a stationary object (we are JUST talking about our reference frame here) observed by us has a constant velocity, even if it...
View ArticleHelp Deriving the Navier Stoke's Eq
hey pf! i was hoping one of you could help me with deriving the navier stokes equations. i know the equations state something like this [tex]\sum \vec{F}=m\vec{a}[/tex] and for fluids we have something...
View ArticleThermodynamic variables
So I have had related questions over the past month, but I would like to ask this question to clarify my understanding. In thermodynamics you work with certain potentials, which are a function of the...
View ArticleLight and sound waves
Anybody has reference paper on light and sound wave's theoretical analogies? I want to read about the analogies and difference between this interactions in terms of waves. Thank you in advance. AGZ
View ArticleThree balls in the plane
Hello everyone, I'm trying to find the exact velocities of three balls in the plane after they collide elastically. I'm assuming arbitrary positive masses and arbitrary positive radii. Of course, three...
View Articlefrequency of photon
Hi, I was wondering what the frequency of a photon is according to maxwell's equations. Does the energy of a photon really oscillate over time? I'm having a hard time picturing what is actually...
View Article[OPTICS] Faraday Rotator with waveplates
Hi all I'm trying to replicate the effect of a 45° Faraday rotator using a series of waveplates instead. I've encountered some difficulties using the jones matrix notation, due to the differencies of...
View ArticleMomentum and K.E.
How can momentum always be conserved while kinetic energy is lost when the collision is inelastic? Since there is a loss of energy why does momentum before collision is still equal to momentum after...
View Article-g or g? and what's -kx?
http://physics.ucsd.edu/students/cou..._solutions.pdf Please go to the website and scroll down to question 75a, why is g=9.8ms^2 is used in the solution instead of g=-9.8ms^2? Isn't it defined by the...
View ArticleW,gas
Hello all, In my physics textbook they discuss work done by ideal gas processes. The equation they give is Wgas = pΔV. I'm trying to figure it out if this is work done ON the gas by the surroundings,...
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