[填空题]
A radioactive nucleus atk 4:n fb5 e698hl.n5vuf dzwum rest decays into a second nucleus, an electron, and n nh39v nf/n1ta neutrino. The electron and neut39v nhf1nntn /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
