The distance of a galaxy from Earth is of the order of `10^25`m. Calculate the order or magnitude of the time taken by light to reach us from the galaxy.

Explanation

Distance of galaxy from earth = `10^(25)m`
Velocity of light (C) `=3 times 10^(8)m//s`
`" "`Time taken by the light (t) `="Velocity of light"/"Distance of galaxy from each"`
`" "`t=d/c rArr t=10^(25)/(3 times 10^(8))=0.33 times 10^(17)s rArr t = 3.3 times 10^(16) sec.`