Assuming that the splitting of a `U^(235)` nucleus liberates of `U^(235)` isotope, and the mass of cal with calorific value of `30 kJ//g` which is equivalent to that the to that for one `kg` of `U^(235)`,
(b) the mass of `U^(235)` isotope split during the explosion of the atomic bomb with `30 kt` trotyl equivalent if the calorific value of troty is `4.1 k J//g`.