The minimum kinetic energy needed by an alpha particle to cause the nuclear reaction `""_(7)^(16)N + ""_(2)^(4)He to ""_(1)^(1) H + ""_(8)^(19)O` in a laboratory frame is n (in MeV) . Assume that `""_(7)^(16)N` is at rest in the laboratory frame . The masses of `""_(7)^(16)N , ""_(2)^(4) He , ""_(1)^(1)H` and `""_(8)^(9)O` can be taken to be 16.006 u , 4.003 u , 1.008 u and 19.003 u respectively where 1 u = 930 `Me V c^(-2) ` . The value of n is ___