[填空题]
A radioactive nucleus at rest decy1o le9y5l so:ays into ambhu2 v-kx (id,*bxk/ second nucleus, an electron, and a neutrino. The electron and neutuxb bidx-hk*m ,v/k2 (rino 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
