I don't understand this equation
So my professor has been using an equation to find the magnetic field of a wire, but the equation is not present in the textbook. it is B = μI/(4πa)(cosθ_1 - cosθ_2) The theta is is an interior angle...
View ArticleFraunhofer diffraction and convolution of two aperture functions
Hello, I'm having some trouble understanding the concept of two function convolution in Fraunhofer diffraction. Let's say I have an aperture function in the shape of some cosine function (which is...
View ArticleFreq in string = freq in air?
If I pluck a string, a wave begins to propagate throughout the string. From experience we know that this produces a sound and this is due to the fact that the oscillation of the wave in the string...
View ArticleBar Pendulum Graph name???
Hi!! WWhen i did the Bar graph experiment, i obtained a parabolic curve on negative and positive x axes (time period^2 vs distance from cg graph). Can anyone tell me what it's actually called, the...
View ArticleFree Expansion of gas
Let's consider free expansion of an Ideal gas into vacuum. We have 2 (insulated) partitions, one with the gas, another vacuum, separated by a stop cock. I lift the cock, letting the gas expand into...
View Articleguitar oscillations? How do they look?
So I recently came across this video in youtube: http://www.youtube.com/watch?v=TKF6nFzpHBU. The vibrations of the string definitely look like sinusoidal waves to me and I know that if a string is...
View ArticleOptical activity
Hi. Does anyone know a book or webpage where I can find specific optic rotation values for solutions with different wavelength? Everywhere I look there's only the value with λ=589nm. Thanks.
View ArticleAmpere's Law
Hello, I am confused as to the physical significance of the dot product of B and ds. Why would we evaluate this scalar product. My textbook has it on here without any motivation for it. Also, why is...
View ArticleUses of superconducters?
I've been hearing superconductors is the future of technology and what not, but then i questioned what the actual uses of superconductors in modern day life. I know that its used in MRI machines but...
View ArticleWhere can we apply the first law of thermodynamics?
Hi people, I have a question. Where can we apply the first law of thermodynamics? I mean is it applicable between 2 equilibrium points? Or between a reversible process? When we consider free expansion...
View ArticleCapacitor having equal charges on plates connected to a battery
Hello I am having a doubt regarding capacitors .I know that when two neutral plates of an uncharged capacitor of capacitance C are connected to a battery of V volts then charges present on the inner...
View ArticleCan two objects having same sign charges attract each other
Hello A neutral charged object can be attracted to a charged body due to electrostatic induction.A charged body will induce charges of opposite polarity in the neutral body ,hence causing attraction....
View ArticleEnergy flux of an EM wave
Hello, The energy density of an electromagnetic wave is [itex]ε_{0}E^{2}[/itex]. To calculate the energy flux, at least in the derivation's I've seen, people just multiply by the speed of the wave,...
View ArticleAim of thermodynamics
Usually I can see what the "aim" is of a certain field of physics. For classical mechanics it is to find the position as a function of time through Newton's law (or similar equations), for quantum...
View ArticleA Pendulum Experiment
If you were to set up two pendulums, identical except that one pendulum had 500 grams of an element with atoms of low mass, and the other with 500 grams of atoms of higher mass, would the two pendulums...
View ArticleGravity/time Comparison
If one planet has a higher gravity than another, would that mean that it would progress through time at a slower rate than the other, being 'deeper' in a gravity well? That it would 'age' slower,...
View ArticleRadiant power spectrum from electroluminence spectrum
Hello everyone! I am having a bit of a problem understanding a paper. Usually the authors use the electroluminescent spectrum to describe an emitter, but in this paper the radiant power is constantly...
View Articlelinac energy
Hi all, this is my first time posting. This may seem too vauge but could a 2m long linac accelerating electrons (with electron gun as source) achive 1.5MeV? I.e. Could it make positrons via pair...
View ArticleJumping off from a high altitude and the landing.
So I recently watched "Warm bodies" with some of my friends. There was a scene where a the man jumps from a relatively high building while holding the girl in his arms, and lands into a pool, while...
View ArticleTrying to understand granular physics (includes fluid physics)
So I want to know what happens when granules are subjected to forces while around other varieties of granules. My interest comes from two places, wanting to gold pan, and how sand surfaces from dirt at...
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