impedance boundary conditions
Hello All. In Acoustics, impedance boundary conditions are defined as Robin conditions (sum of normal derivative of the complex acoustic pressure plus the pressure itself); the right-hand side is a...
View ArticleFuel consumption increases during winter?
I guess that if the answer is "yes" then the difference will be neglectable, but anyway... I was wondering if during winter, fuel is less efficient than summer. During summer, there is some extra...
View ArticleQuestions About Inductors
Hello everybody, First of all I want to thank you all for this great forum. My question is if a superconductor inductor is charged with a certain voltage and then it is open circuited what will happen....
View ArticlePressure vessel cascading with a regulator?
Hi all, I am trying to determine what approach to use to solve the following scenario: I have a pressure vessel with pressure P1 and volume V1. I have another vessel of pressure P2 and volume V2....
View ArticleEm wave going into metal.
A metal box will block most EM waves. Is this because the oscillating E field will be canceled when in contact with the conductor. And because the oscillating E field is the source of the changing B...
View ArticleProducing Alternating current of high Frequency.
As the title suggests, how are very high frequency AC produced? A AC generator must have a limit to the rotation velocity of the coil, mustn't it? Any help would be appreciated. Thanks.
View ArticleGeneralized coordinates - Rotating pendulum
My question is kinda simple but it has been causing me some trouble for a while. In the problem of the pendulum rotating about an axis, why isn't the angle of rotation about the axis a generalized...
View Article[At' Pressure] Glass of water held upsidedown
Hey, I'm sure you are all familiar with the experiment where you take a glass of water , put a some seal on it and then turn it upside down. Due to the (atmospheric pressure) - (the air pressure in the...
View ArticleCharging by conduction with and odd net charge?
Hello, I've just got a quick question about charging an object by conduction. I've been studying for my final and I came across a problem that I can't really see how to solve. Say you have two...
View ArticleWhy Thomson scattering calls for a "size-changing" electron?
From my limited understanding of Thomson scattering, it only works for wavelengths comparable to the size of the electron. Because scattering was observed at a variety of wavelengths, it was assumed...
View ArticleWhat is a Self Consistent Electric Field?
Hi, Ive been doing some reading into 1 dimensional plasma numerical simulations and they keep referring to solving for a "self-consistent" field. If the simulation is in one dimension with periodic...
View ArticleSound diffraction
Hi, my friends. Today, I come up with a question suddenly. It is about Sound diffraction. why can we hear someone's voice even when he is in a closed office. Many books says that it is because of Sound...
View ArticleCan I get a 40KN force from a hydraulic cylinder powered by an electric motor?
Im thinking of designing a tipping trailer for a car. I need a force of 40KN exerted to tip but would this be too much for driving with an electric motor powered by the car battery. If not what size of...
View Articleelectromagnetic induction between 2 coils problem.
We know that 1)a change in current and voltage in a coil may result in induction in other stationary coil..this induction is directly related to frequency..ie The higher the frequency the more intense...
View ArticleAcceleration v Constant Velocity
This question might seem strange or dumb.. At least it does in my mind, however I phrase it.. Anyway, I'm wondering about the reasons for acceleration being felt and constant velocity not being felt by...
View ArticleHaving trouble understanding what tension is
Hi, I undersand that tension is the force exerted on an object by a string or rope when pulled. Where I get confused is when I'm asked to find the tension at a point along a rope or tension in a...
View ArticleMaths prep for Electromagnetism unit
Early next year I will be beginning an Electromagnetism unit. However, I think I should refresh my maths over the summer break first. Here is the Unit Description from the uni website: A detailed...
View ArticleTemperature Concept?
what is the difference between emperical and thermodynamic temperature?
View ArticleConditions for an antinode?
Hi, If I have two sinusoidal waves with the same frequency, wavelength and amplitude, travelling along the same line in opposite directions, the net displacement of the resulting standing wave wave is...
View Articleair resistance, dimensional analysis confusion
Hi. Consider the basic eq for a falling body with air resistance dv/dt=g-kv/m I dont understand air resistance as a force, since it seems irreconcilable to the force equation F=ma. How is a force a...
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