The farthest objects in out universe discovered by modern astronomeres are so distant that light emitted by them takes billions of year to reach the earth. These object (known as quasers) have may puzzling features, which have yet not been satisfactorily explained. What is the distance in km of a quasar form which light takes 3.0 billion years to reach us?

Explanation

Here, x= ? Time taken t =3.0 bilion years `=3xx10^9 yr = 3xx10^9xx365xx24xx60xx60s`
vel. Of light in vacuum, `c = 3xx10^8 m//s = 3xx10^5 km//s`
As distance = velocityxx time :. `X= (3xx10^5)xx3xx10^9xx365xx24xx60xx60 km = 2.84xx10^(22)km`