calculate the number of joules that can be obtained from the fissioning of 1 kg of 235u, assuming 198 mev average energy release per fission. how much energy (in joules) can be obtained from the 235u in one kg of natural uranium? calculate how much energy (in joules) can be obtained from burning 1 kg of coal. what is the total amount of energy contained in the known us resources of coal and 235u, respectively?