A new unit of length is chosen such that the speed of light in vacuum is unify. What is the distance between the sun and the earth in terms of the new unit, if light takes 8 min and 20 s to cover this distance?

The speed of light in vacuum © = 1 new unit of length /s

Time taken by light to reach the earth

t = 8 min + 20 s = (8 X 60 + 20) s = 500 s

Distance between the sun and the earth = Speed of light x Time

x = c x t = 1 new unit of length/ s x 500 s = 500 new unit of length