Question

A new unit of length is chosen such that the speed of light in vacuum is unity. 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

Answer 1

Given, the speed of light in vacuum is unity and the time taken by the light to cover the distance between the Sun and the Earth is 8 min and 20 sec.

Let the speed of light represent be c and the time travel by light be t.

The distance between the Sun and the Earth is,

distance=speed ×time d=c×t

Substitute the given value in above equation.

d=c×t d=( 1 m/s )( ( 8 min )( 60 s 1 s )+20 s ) =( 1 m/s )( 500 s ) =500 m

Hence, the distance between the Sun and the Earth is 500 m .