일반물리학 2 — Maxwell's Equations; Magnetism of Matter: Problem 46

46 A 0.25 T magnetic field is applied to a paramagnetic gas whose atoms have an intrinsic magnetic dipole moment of $1.0 \times 10^{-23}$ J/T. At what temperature will the mean kinetic energy of translation of the atoms equal the energy required to reverse such a dipole end for end in this magnetic field?