Answer
$2.6\times10^{-5}g$
Work Step by Step
The power (wattage) multiplied by the time is the energy.
The mass is found by using equation 26–7.
$$E=Pt=mc^2$$
$$m=\frac{Pt}{c^2}=\frac{(75W)(3.16\times10^7s)}{(3.00\times10^8m/s)^2}\frac{1000g}{kg}$$
$$=2.6\times10^-5g $$
