



 
Hi John, We had a similar question a while ago about a roll of paper. Have a look at my response to this question. The radius of the roll is
In your example L = 3000 × 12 = 36000 inches, t = 0.005 inches and r = 6/2 = 3 inches. Thus
Thus the diameter of the roll is 2 × 6.95 = 16.28 inches. Penny  


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