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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 .
Solution
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
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