A new unit of length is chosen such that the speed of light in vecuum 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 sec. to cover the distance ?

Options

A. 500
B. 300
C. 200
D. 100

Answer

A

Explanation

The speed of light in vacuum (c) =1
(new unit of `"length" s^(-1)`)
time taken by liht to reach the earth
t=8 min +20s
`=(8xx60+20)s=500s`
`:.` Distance betweenteh sun and the earth = Speed of light `xx` Time
`x=cxxt`
=1 (new unit of engths `s^(-1)`) `xx500 s`
=500 new unit of length.