How long would it take a radio wave of frequency `6xx10^(3) sec^(-1)` to travel from mars to the earth, a distance of `8xx10^(7)km` ?

Answer

4 min 26 sec

Explanation

All radiation in vacuum travel with the same speed, i.e., `3 xx 10^(8) ms^(-1)`
Distance to be travelled from Mars to the Earth `= 8 xx 10^(7) km = 8 xx 10^(7) xx 10^(3) m (1 km = 10^(3) m)`
`:.` Time taken `= (8 xx 10^(7) xx 10^(3))/(3 xx 10^(8)) = 2.66 xx 10^(2) sec = 4` min 26 sec