An orbital science probe uses a solid-state laser that is cooled by allowing liquid nitrogen to boil at its boiling point. The vaporised nitrogen gas is vented into space. Over a continuous laser firing duration of 15.0 minutes15.0\text{ minutes}15.0 minutes, the mass of liquid nitrogen in the coolant reservoir decreases.
Explain how system engineers could use this mass difference, along with the standard value for the specific latent heat of vaporisation of nitrogen, to estimate the average rate of waste heat generation (thermal power) by the laser in kilowatts.
Practise AQA GCSE Physics Internal energy and energy transfers with exam-style questions for Foundation and Higher tier. 48 questions covering Internal energy, Temperature changes in a system and specific heat capacity, and Changes of state and specific latent heat, matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.