試題詳解

(17)A neutron (mass 1.01 u) strikes a deuteron (mass 2.01 u), and they combine to form a tritium nucleus (mass 3.02 u). If the neutron's initial velocity was 34.5î + 24.9ĵ Mm/s and if the tritium leaves the reaction with velocity 21.6î + 42.6ĵ Mm/s, what was the deuteron's velocity?
(A)(10.90î + 26.57ĵ) Mm/s
(B)(20.64î + 84.26ĵ) Mm/s
(C)(15.12î + 51.49ĵ) Mm/s
(D)(41.53î + 121.87ĵ) Mm/s
(E)(50.52î + 74.89ĵ) Mm/s