How long is this roll of tape?
Posted: July 7th, 2021, 1:08 pm
Almost certainly a simple one for the mathematical types around here, but this is a practical problem which I think (hope!) I've got a good-enough-for-me answer to but thought I'd throw in as a "How do you figure this properly?" question ... and to double check my good-enough-for-me answer!
https://www.steelroofsheets.co.uk/products/20mm-x-9mm-grey-self-adhesive-pvc-foam-tape-8m-roll/
I've been sent a roll of adhesive foam tape similar to the above (but not that one). It's a gift and I'm not sure how long it is, and prefer to measure its length myself and just email back a grateful "Thanks! That's great!" rather than a question about it. Of course I could stretch it out, measure it, and then rewind it before putting it in the cupboard for later use, but being adhesive backed that risks all sorts of hassles, from it falling onto the floor and picking up carpet fluff to personal entanglement, as well as possibly weakening the adhesive.
So instead, measuring the roll itself as is, the diameter across the whole disc is 20cms.
The diameter of the outside of the inner plastic ring (i.e. the diameter of the inside of the foam roll itself) is 8cms.
Counting from the outside one to the inside one, there are 10 "rings" (not actually rings of course) of tape.
So, my rough-and-ready take on it (not going for massive accuracy here! ) is that the outermost ring of tape is 20*Pi = ~63cms long, and the innermost is 8*Pi = ~25cms long. So, the average length of a ring is (63+25)/2 = 44cms and there are 10 rings so I have around 4.4 metres of tape.
Fair enough, or likely to be way off? And what's the more accurate way of calculating it?
https://www.steelroofsheets.co.uk/products/20mm-x-9mm-grey-self-adhesive-pvc-foam-tape-8m-roll/
I've been sent a roll of adhesive foam tape similar to the above (but not that one). It's a gift and I'm not sure how long it is, and prefer to measure its length myself and just email back a grateful "Thanks! That's great!" rather than a question about it. Of course I could stretch it out, measure it, and then rewind it before putting it in the cupboard for later use, but being adhesive backed that risks all sorts of hassles, from it falling onto the floor and picking up carpet fluff to personal entanglement, as well as possibly weakening the adhesive.
So instead, measuring the roll itself as is, the diameter across the whole disc is 20cms.
The diameter of the outside of the inner plastic ring (i.e. the diameter of the inside of the foam roll itself) is 8cms.
Counting from the outside one to the inside one, there are 10 "rings" (not actually rings of course) of tape.
So, my rough-and-ready take on it (not going for massive accuracy here! ) is that the outermost ring of tape is 20*Pi = ~63cms long, and the innermost is 8*Pi = ~25cms long. So, the average length of a ring is (63+25)/2 = 44cms and there are 10 rings so I have around 4.4 metres of tape.
Fair enough, or likely to be way off? And what's the more accurate way of calculating it?