2 k λ 0 d [ R 2 + d 2 − 2 R d + R d ⋅ π 2 100 − R 2 + d 2 − 2 R d ] v = 2 k π λ Q m {\displaystyle {\frac {2k\lambda _{0}}{d}}\left[{{\sqrt {R^{2}+d^{2}-2Rd+{\frac {Rd\cdot \pi ^{2}}{100}}}}-{\sqrt {R^{2}+d^{2}-2Rd}}}\right]v=2{\sqrt {k{\frac {\pi \lambda Q}{m}}}}}
![{\displaystyle {\frac {2k\lambda _{0}}{d}}\left[{{\sqrt {R^{2}+d^{2}-2Rd+{\frac {Rd\cdot \pi ^{2}}{100}}}}-{\sqrt {R^{2}+d^{2}-2Rd}}}\right]v=2{\sqrt {k{\frac {\pi \lambda Q}{m}}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/63098ca5ed1bf200d5f07d6ea2690492d9cceb8a)
