Question

It takes time 8 min for light to reach from the sun to the earth surface . If speed of light is taken to be `3 xx 10^8   "m/s"^-1` , find the distance from the sun to the earth in km .

Answer 1

Given,

Speed of light = `3 xx 10^8` m/s

Time taken to reach the earth = 8 min = 480 s

We know,

Distance = speed × Time

= `3 xx 10^8 xx 480`

= `1440 xx 10^8  "m" = 1440 xx 10^8 / 10^3  "km" = 1440 xx  10^5  "km"`

= `1.44 xx 10^8` km