Partition function related to number of microstates
Hi, I have a question about the partition function. It is defined as ## Z = \sum_{i} e^{-\beta \epsilon_{i}} ## where ##\epsilon_i## denotes the amount of energy transferred from the large system to...
View ArticleHow do you measure the air pressure inside a balloon?
Unfortunately when I google the answer, the results are just how to use a balloon to measure air pressure. I want to be able to monitor the internal pressure of a balloon using a digital barometer. 1)...
View ArticleDerivation of rotational mechanics
Hi: I was wondering, is it possible to show that all rotational mechanics are consequences from translational mechanics? aka showing that they are equivalent? thanks!
View ArticleAngular Momentum of a sliding disc about a point on the floor
Hi everybody, A seemingly straightforward example from lecture is causing me some confusion. The example was about calculating the angular momentum of a sliding disk (not rolling) about a point on the...
View ArticleEntropy of a continuous system
How could the entropy of a continuous system, like the electromagnetic field, be defined? Obviously you can't use something like the log of the phase space volume, but I can't think of anything that...
View ArticleAcoustic impedance- pressure and velocity
I find that the acoustic impedance is given by Z= Pressure/ Velocity I read that the acoustic impedance of a plane propagating wave is given by Z = ρ0c. What is ρ0 and c? Thanks a lot
View ArticleDifference between particle velocity and phase velocity
According to wiki- For surface gravity waves, the water particle velocities are much smaller than the phase velocity, in most cases. Then have shown this diagram...
View ArticleSingle frequency- phase and group velocity?
Let's consider a single frequency signal of frequency say 'f'. If the wave is propagating through a medium (EM wave with a velocity of 'c') then what will be the phase and group velocity? I believe...
View ArticleDeriving electromagnetic fieldfor point charge
Hi all, I was going through the derivation for the electromagnetic field of point charges by Griffith(Introduction to electrodynamics page 437). I'm missing minus sign somewhere: The book says...
View ArticlePotential Difference and Capacitors
So I am having some trouble conceptualizing potential difference, and how to calculate it without integrating the E-Field. My problem is how exactly would you calculate the potential difference between...
View ArticleRigid Body Dynamics R&D help!
Hey guys; I am new to the forums. I am an effects artist who's working a Rigid Body Dynamics project and I may be able to use some of you guys' expertise while I'm building these simulations. As I...
View ArticleWavepacket Evolution
I had a few questions regarding the time evolution of wavepackets of the form ∫ dk*A(k)*cos(kx-wt), where w = w(k) If the group velocity is zero, i.e; dw/dk evaluated at k' = 0, where k' the central...
View Articlecan someone clarify and shed some light about these two statements
If every dynamic variable in a physics problem is a measurement derived from a particular coordinate system how do you explain the contradiction both statements 1 and 2 imply if they are both...
View Articlewhat are the hamilton equations of motion for homogeneous lagrangians?
For a Lagrangian [itex]L(x^k,\dot{x}^k)[/itex] which is homogeneous in the [itex]\dot{x}^k[/itex] in the first degree, the usual Hamiltonian vanishes identically. Instead an alternative conjugate...
View ArticleMawell equations with monopoles
Hi all, Suppose magnetic monopoles exist, how would the maxwell equations be solved? Because the divergence of B is no longer zero, we can not use the vector potential, can we? Do you just solve for...
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Efficiency to move a curve shape
Fig 1 : the blue volume has a lot of very small spherical balls in it. Balls are under pressure from external system (weight or other), the potential energy is always the same because the blue volume...
View Articlecalculate max depth in water a hollow steel sphere can withstand
Any help is appreciated, I'm really just trying to figure out if it can withstand 300 meters but it would be useful to see how/if a max depth can be calculated. diameter: 20M steel density: 7850 kg/m^3...
View ArticleProof of F.s = Work Done by F
How would one prove W = F.s and why would only F.s be conserved (in energy conservation) and why not F.s^2, or F.s^3? One possibility is by experimental observation and verification. But how would one...
View ArticleWhat do you know about ion thrusters?
So I am planning to design and construct a small scale ion thruster for an independent study class i am taking at my local high school. I have spent many hours researching the subject, so i feel like i...
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