Einstein’s Mass-Energy Equivalence – Practice
Questions:
1) In a particular reaction in the Sun, a proton fuses with deuterium. 20MeV are produced as a result of this nuclear reaction.
a) How much energy is released in joules?
b) How much mass is lost as a result of this reaction?
2) 8.16 MeV were released as a result of a number of electron-positron annihilations. How many particles were involved to produce this energy?
3) When 1kg of coal is burnt it releases 3.4 × 107 J of energy. How much mass is lost when 1 tonne of coal is burnt in a power station?
Quick Answers:
1a) 3.2 × 10−12 J b) 3.6 × 10−29 kg
2) 16 particles (8 electrons and 8 positrons)
3) 3.8 × 10−7 kg
Worked Answers: