Answer:
L= 12 light years
Step-by-step explanation:
for length dilation we use the formula
![L=L_0\sqrt{1-(v^2)/(c^2) }](https://img.qammunity.org/2020/formulas/physics/college/lims6mr0vuvobkwprjj102cr8fzvjk04w9.png)
now calculating Lo
Lo = 12.5×365×24×3600×3×10^8
= 1.183×10^17 m
now putting the values of v and Lo in the above equation we get
![L=1.183*10^(17)\sqrt{1-(0.28c^2)/(c^2) }](https://img.qammunity.org/2020/formulas/physics/college/s2zb2r4tlk8sdwmmxvccrnl8sf9285vn5y.png)
= 1.136×10^17 m
L=
m
so L= 12 light years