Abeam of ag atoms, each with spin-1/2, is prepared in a way that 60% of the atoms are in the sz = +ħ/2 eigenstate of sz, and 40% are in the eigenstate sx = -ħ/2 of sc. (a) obtain the density matrix at t = 0, in the basis of eigenstates of sz. (b) admit that the atoms are subjected to a magnetic field b = boû, so that the hamiltonian reads, h = us. b (u is the magnetic moment of an atom). obtain the density matrix at time t, in the basis of eigenstates of sz. (c) calculate (sz) at times t = 0 and t.

The discovery that the universe appears to be expanding led to a widely accepted theory called a.) the big bang theory b.) the doppler effect c.) hubble’s law d.) solar nebular theory e.) the seyfert theory

An internally reversible refrigerator has a modified coefficient of performance accounting for realistic heat transfer processes of where qin is the refrigerator cooling rate, qout is the heat rejection rate, and is the power input. show that copm can be expressed in terms of the reservoir temperatures tc and th, the cold and hot thermal resistances rt,c and rt,h, and qin, as where rtot rt,c rt,h. also, show that the power input may be expressed as 1.39 a household refrigerator operates with cold- and hot-temperature reservoirs of tc 5 c and th 25 c, respectively. when new, the cold and hot side resistances are rc,n 0.05 k/w and rh,n 0.04 k/w, respectively. over time, dust accumulates on the refrigerator’s condenser coil, which is located behind the refrigerator, increasing the hot side resistance to rh,d 0.1 k/w. it is desired to have a refrigerator cooling rate of qin 750 w. using the results of problem 1.38, determine the modified coefficient of performance and the required power input w under (a) clean and (b) dusty coil conditions. internally reversible refrigerator qout qin w high-temperature reservoir low-temperature reservoir th th,i tc,i tc high-temperature side resistance low-temperature side resistance w qin th tc qinrtot tc qinrtot copm tc qinrtot th tc

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?