How long is the string in cm?

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How long is the string in cm?

A cylinder 60cm high has a cyrcumfernce of 20cm. A string makes exactly 4 complete turns round the cylinder while its two ends touch the cylinder's top and bottom. How long is the sting in cm?

2006-10-03 07:04:42 · 2 answers · asked by Dianthony C 1 in Science & Mathematics ➔ Mathematics

2 answers

4 *20 + 60 or about140

2006-10-03 07:13:01 · answer #1 · answered by CHAZ2006 3 · 0⤊ 0⤋

sqrt ((number of turns * circumference)^2 + height^2) = length of string
-or-
sqrt((4*20)^2 + 60^2) = sqrt(6400 + 3600) = sqrt(10000) = 100

2006-10-05 18:13:14 · answer #2 · answered by Math geek 3 · 0⤊ 0⤋