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Question
A radio signal, sent towards the surface of the moon, is received in 2.5 seconds. If the speed of the radio waves is 3 × 108 ms−1, find the distance of the moon from the earth.
Solution
Let ‘d’ be the required distance. The radio waves then travel a total distance 2d (to and from the moon) in 2.5 seconds.
Hence,
`(2"d")/2.5` = Speed = 3 × 108
d = `3xx10^8xx2.5/2` metre
= 3.75 × 108 metre.
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