[填空题]
A radioactive nucleus) zsekxt,f o(/; eiajqnifl p+* i/s(8at rest decays into a second nucleus, an electron, and a neutrino. The electron and neutrino are emitted at right angles q;/*8elpj(iin f s +iaand 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
