Answer:
1.31022×10⁻³⁴ kg
Explanation:
Difference in energies = 1189.4-1115.7 MeV = 73.7 MeV
Convert this energy to Joules
1 MeV = 1.6×10⁻¹⁹ J
73.7 MeV = 73.7×1.6×10⁻¹⁹ J = 117.92×10⁻¹⁹ J
c = Speed of light = 3×10⁸ m/s
From Einstein's equation
E = mc²
[tex]m=\frac{E}{c^2}\\\Rightarrow m=\frac{117.92\times 10^{-19}}{(3\times 10^8)^2}\\\Rightarrow m=1.31022\times 10^{-34}\ kg[/tex]
∴ Difference in their masses is 1.31022×10⁻³⁴ kg
