Respuesta :
Given:
Distance of alpha century = 4 light year
Speed of light = 3 × [tex] 10^{8} [/tex] m
To find:
Time taken by light to reach earth = ?
Formula used:
Distance = speed × time
Solution:
Distance = 4 light year
Converting distance from light year into meter
1 light year = 365 × 24 × 60 × 60
4 light year = 4 × 365 × 24 × 60 × 60× 3 ×[tex] 10^{8} [/tex]
As we know,
Distance = speed × time
s = v × t
Where s = distance
v = velocity
t = time
So,t = [tex] \frac{s}{v} [/tex]
t = [tex] \frac{4 × 365 × 24 × 60 × 60× 3 ×[tex] 10^{8} [/tex]}{3 ×[tex] 10^{8}} [/tex]
t = 4 × 365 × 24 × 60 × 60 second
t = 4 year
Thus, Time taken by light to reach earth from alpha century is 4 earth year.