Imagine you would have to put a rope around the moon. Since the moon is 1,738,000 metres in diameter, this is a hard task. Finally you have managed to get the rope around the moon but... it is one meter short.

You decide to dig a groove all around the moon, so that the shorter rope suffices. How deep must this groove be? (Assume the Moon to be a perfect sphere.)

The circumference of the moon is 2ðR

length of the rope is L

L=2ðR -1

now after groving

radius is say r it gets reduced

so again as its same rope

L=2ðr and  L = 2ðR-1

so R-r = 1/2ð

Posted by prashant on 2004-03-29 07:39:08