A Light Year is the distance travelled by light in vacuum in one year. How many metres are there in one light year?  (Noor asked)

Answer:

Speed of light in vacuum is 3 x 10⁸ m/s

1 year = 365 days = 365 x 24 hours=365 x 24 x 60 minutes = 365 x 24 x 60 x 60 seconds

We know that distance = speed x time

Therefore,

1 LY = 3 x 10⁸ x 365 x 24 x 60 x 60 m = 9.460528405×10¹⁵ m