Answer:
1) Mass that needs to be converted at 100% efficiency is 0.3504 kg
2) Mass that needs to be converted at 30% efficiency is 1.168 kg
Step-by-step explanation:
By the principle of mass energy equivalence we have
![E=mc^(2)](https://img.qammunity.org/2020/formulas/physics/high-school/nwasal9swe4f48dzslu4zvs6vx4kg2sub6.png)
where,
'E' is the energy produced
'm' is the mass consumed
'c' is the velocity of light in free space
Now the energy produced by the reactor in 1 year equals
![Energy=Power* time\\\\\therefore Energy=1* 10^(9)* 365* 24* 3600\\\\Energy=31.536* 10^(15)Joules](https://img.qammunity.org/2020/formulas/physics/college/i0pvyddqlonvdjt0jwd2j3iyh6tuw0ipp8.png)
Thus the mass that is covertred at 100% efficiency is
![mass=(Energy)/(c^(2))\\\\mass=(31.536* 10^(15))/((3* 10^(8))^(2))\\\\mass=(31.536* 10^(15))/(9* 10^(16))\\\\\therefore mass=0.3504kg](https://img.qammunity.org/2020/formulas/physics/college/xgtxnpuv76dgt64wqzzcuepvwuivxc3zms.png)
Part 2)
At 30% efficiency the mass converted equals
![mass|_(30)=(mass|_(100))/(0.3)\\\\mass|_(30)=(0.3504)/(0.3)\\\\mass|_(30)=1.168kg](https://img.qammunity.org/2020/formulas/physics/college/wfn0jh1nhklqmzv4o706tmgrf329xz3w1p.png)