Answer
105.2 MeV.
Work Step by Step
The kinetic energy comes from the mass decrease. From Table 44.2, we see that the $\mu^-$ has a mass of $105.7 MeV/c^2$. Subtract the electron mass of $0.511 MeV/c^2$ and find a mass difference of $105.2 MeV/c^2$.
The energy released is 105.2 MeV.
