I'm reading about the theory behind MRI, specifically from Farr's Physics for Medical Imaging, 2nd Edition, by Allisy-Roberts and Williams.
According to this book, the spins of the free protons in a sample line up, either parallel or antiparallel, with the externally applied magnetic field. In...
The energy difference between two nuclear spin states in an external magnetic field B is given by
\Delta E = \gamma \hbar B
Why does resonant absorption of electromagnetic radiation by nuclear spins take place at the Larmor frequency? Shouldn't it be that the photon energy is equal to the...
I don't think Part II is straightforward, because you need to relate the acceleration of the 1 kg mass with that of the 2 kg mass. But this relation is not trivial.
If we let the distance between the 2 kg mass and the base of the pulley be x (which starts off at 2 m), and the length of the...
Problem
A mass of 2 kg is held at rest on a rough horizontal table with coefficient of friction μ = 0.5. A string is attached to the mass and is hung over a smooth pulley. A 1 kg mass is suspended from the other end of the string. The top of the pulley is at a height of 1 m above the table...
Yes, that makes sense.
So the acceleration of the centre of mass of the BC composite aBC is given by 3aBC = 2aB + aC (this is just saying the rate of change of momentum of the composite is equal to sum of the rates of change of momentum of B and C separately).
So we can use Newton's 2nd...
Question
A string is hung over a fixed pulley, and a 4kg mass is suspended from one end of the string. The other end of the string supports a massless pulley, over which a second string is hung. This string has a 2kg mass attached to one end, and a 1kg mass attached to the other end. See the...