A pulsed laser emits light pulses, each of energy 5.0kJ and duration 10ns. During a materials-processing run the laser fires 1.0×106 identical pulses. Use c=3.0×108ms−1 and 1u=1.66×10−27kg.
(i) Calculate the total energy delivered by all the pulses.
(ii) Compute the corresponding mass decrease in the laser medium, expressing your answer: (a) in kilograms, and (b) in atomic mass units (u).