[填空题]
A radioactive nucleus at rest d csihqq huwloa c5q/ ct1,v6cr9-q: :.ecays intogigv7n h;b s;w 4uum89*oc /lo a second nucleus, an electron, and a neutrino. The electvi8h7s;4 ngcom uw/l* b;9og uron and neutrino are emitted at right angles and have momenta of $9.30\times10^{-23}kg\cdot m/s$ and $5.40\times10^{-23}\mathrm{~kg}\cdot\mathrm{m/s}$ respectively. What are the magnitude and direction of the momentum of the second (recoiling) nucleus? $ \times10^{-22}$ $^{\circ} $ from the momentum of the electron
