Solution

$14.5.2$ The solar radiation power $W$ is close to $4 \cdot 10^{26}$ watts. Estimate the mass lost
by the Sun due to radiation over the course of a second.

The energy emitted from the sun is:

\begin{equation} E = P \cdot 1 s = 4 \cdot 10^{26} \end{equation}

Using the equivalency between mass and energy we have:

\begin{equation} m = \frac{E}{c^2} = 4,4 \cdot 10^9 g \end{equation}