Recent content by hungry_r2d2

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    Feshbach resonance for Li: repulsive and attractive?

    Hello, I am looking into the Feshbach resonance for Fermi gas (Lithium in particular). The following is unclear: Is it correct to say that there is a repulsive interaction between the atoms in the regime, where the scattering length is positive? I have found various sources saying so...
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    Understanding kinetic energy under Galilean transformations

    All right, I think I now understand the problem. The main point is that inside the train momentum is always conserved, even if a jet pack is involved. I attach an a more complete solution in the PDF. I acknowledge major input by R.K.
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    Understanding kinetic energy under Galilean transformations

    Again, thanks for help. Sorry for bumping, but I still don't get it. Imagine that the passenger powers up his jet pack and gains E worth of kinetic energy in the train coordinate system. (We may assume 100% efficiency and negligible loss of mass in the jet pack). Thus the passenger gains the...
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    Understanding kinetic energy under Galilean transformations

    Thanks for the answer, however it doesn't answer my question (probably because I formulated it unclearly). I realize it is possible to calculate the velocity change of the train due to the truck by imposing conservation of impulse. However, it is possible to overcome this effect by giving the...
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    How can I track positions from acceleration values?

    Answer from also a n00b: So your position is x=x_0 + v_0 t + at^2/2 where x0 is the initial position, v0 is the initial velocity (i guess you might want to set them to zeros), and then a is the acceleration that your device is giving, while t is the time. Does this help? P.S. I've noticed...
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    Understanding kinetic energy under Galilean transformations

    Hello, Consider the following two situations. There is a train of mass M, going at V=10 m/s with respect to the train station. There is a mass m passenger on that train, who starts walking at v=1m/s parallel to the direction of the train motion. The kinetic energy of this system...
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