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.)

(In reply to Got to be wrong! by Mike)

Your formula (πr² = π[d/2]²) is for the area, not the circumference of a circle. The correct formula is C = πd = 2πr

Try again

Posted by TomM on 2002-07-24 07:34:23