$${d = \frac{1}{2} \left( \frac{\mu_B (dB/dz)}{M} \right) \left( \frac{w}{v} \right)^2 = \frac{\mu_B (dB/dz)w^2}{2 Mv^2} \\ = (9,27 \times 10^{-24}\, \mathrm{J/T})(1,4 \times 10^3\, \mathrm{T/m}) \\ \times \frac{(3,5 \times 10^{-2}\, \mathrm{m})^2}{(2)(1,8 \times 10^{-25}\, \mathrm{kg})(750\, \mathrm{m/s})^2} \\ = 7,85 \times 10^{-5}\, \mathrm{m} \approx \underline{\underline{0,08\, \mathrm{mm}}}}$$