1. The problem statement, all variables and given/known data Kindly refer to part (c). The woking should be power/0.35 (what I think according to the graph). But the answer is power (that is the answer of part b) divided by 0.02 2. Relevant equations I have used the ratio method simply 3. The attempt at a solution According to part (b), the amount of heat energy needed needed per second is 4.68 Joules (answer to part b). Now the gradient of the graph indicates that the mass loss per second is 0.35g/s. So we can imply the 4.68 Joules are needed to boil off 0.35g of liquid Nitrogen in one second. Then applying ratio, we can calculate for 1g. The correct answer to this question applies the same method but uses 0.02 instead of 0.35. Why is that so? Where did it come from?