AQA A Level Physics Nuclear Physics Answers 2

1 A Level Physics Nuclear Physics 2 (Answers) Total Marks:/30 2022 AQA A Level 2 1. The equivalence of mass and energy, quantified by Einstein’s famous equation E = mc2, underpins all nuclear reactions. (a) Calculate the energy equivalent of the following: i. The mass of an electron. Total for Question 1: 13 [2] ii. A human weighing 700 N. [2] [4] (b) Calculate the final mass when an 4He nucleus is taken from rest to having kinetic energy of 5.0 MeV. Will this change be an increase o2r a decrease? Solution: 6.7 × 10−27 Kg An increase. Solution: 8.20 × 10−14 J Solution: 6.42 × 1018 J 3 (c) Calculate the minimum photon energy required for pair production, giving your answer in units of MeV. Give an example of when pair production is useful. [5] Solution: 1.02 MeV It is an absorption mechanism for x-rays. Without absorption there would be no contrast in a medical x-ray image.