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HNQ
4:43 AM
1
Q: Conservation of Mass and Energy

Dude156I was thinking about some physics (relativity in particular), when it suddenly occurred to me that all my life I had been balancing chemical equations assuming conservation of mass, but I was disregarding energy! For example, consider combustion: $$CH_4 + 2O_2 >>> 2H_2O + CO_2 + {Energy}$$ Howe...

 
 
7 hours later…
HNQ
11:44 AM
1
Q: In the quantum hamiltonian, why does kinetic energy turn into an operator while potential doesn't?

UriAcevesWhen we go from the classical many-body hamiltonian $$H = \sum_i \frac{\vec{p}_i^2}{2m_e} - \sum_{i,I} \frac{Z_I e^2 }{|\vec{r}_i - \vec{R}_I|} + \frac{1}{2}\sum_{i,j} \frac{ e^2 }{|\vec{r}_i - \vec{r}_j|} + \sum_I \frac{\vec{p}_I^2}{2M_I}+ \frac{1}{2}\sum_{I,J} \frac{Z_IZ_J e^2 }{|\vec{R}_I - \...

 
HNQ
12:23 PM
2
Q: Is it possible that an electric field exists like this?

The Angel of ElistonIs it possible for an electric field exist,that its electric field intensity continuously increases(like E=kx),while all the E-vectors pointing the same direction(I mean,parallel vectors)?

 
 
10 hours later…
HNQ
10:20 PM
2
Q: Is it work or heat?

DimitrisOne student of mine has found one question in a book of thermodynamics (1st year university level). Work or Heat? You grab a bottle of juice and shake it thoroughly. Is this an example of a work or a heat interaction? Recall that work can be described with mechanical or electromagnetic va...

 

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