| Forum Home | ||||
| PC World Chat | ||||
| Thread ID: 140486 | 2015-10-21 04:55:00 | Horrible maths sort of thing | pctek (84) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1410269 | 2015-10-21 04:55:00 | What sort of calculation, specifically, can you have to calculate the following. You have a big roll of stuff, imagine plastic wrap or something. It starts off as x metres in length. Someone then cuts off a random amount, from either the diameter or mass, you then figure out how much is left. Not sure it needs to be totally 100% accurate but near enough. I have no idea how to even begin to do that....light years beyond my maths skills. |
pctek (84) | ||
| 1410270 | 2015-10-21 05:03:00 | By weight I would think. Weigh before cutting divide by the known length in MM then weigh again after cutting said random amount. |
gary67 (56) | ||
| 1410271 | 2015-10-21 05:19:00 | Yeah as gary67 says weight; easy, quick, accurate (as moisture/humidity uptake may be involved). Also specs for papers (as in 0.5 to 10 ton),and films are based on mass. In NZ paper/pulp mills, and plastic film factories, we use to grade large mass based on weight, or more specifically gsm (or kgsm) - kilo grams/sq. meter. Then if needed can convert to length, based on density and thickness. | kahawai chaser (3545) | ||
| 1410272 | 2015-10-21 05:30:00 | Mmm, husband suggested that, but person concerned says nothing to weigh it with and too big anyway... So diameter? Sounds horribly complicated to me. |
pctek (84) | ||
| 1410273 | 2015-10-21 05:31:00 | As gary67 says, weigh it. But... what do you mean by "from either the diameter or mass"? Lets assume the total length is R. First, weigh the entire roll: weight = W Now cut a length r from the roll and weigh that: weight = w Assuming the material is uniform and it constitutes the entire roll (no heavy central core or anything like that) then W/R = w/r So the length remaining is R - r = r x(W/w -1) |
Jayess64 (8703) | ||
| 1410274 | 2015-10-21 06:00:00 | www.handymath.com or www.had2know.com Thanks Google... |
user (1404) | ||
| 1410275 | 2015-10-21 06:05:00 | www.handymath.com or www.had2know.com Thanks Google... Ah thanks, just the thing apparently. |
pctek (84) | ||
| 1410276 | 2015-10-21 07:33:00 | Looks like it's sorted but wouldn't it be easier to just measure how much was taken off at the time rather than calculate it after the fact ? Also weight would work if you took off a metre and weighed it, then used that weight/m to calculate what was used based purely on the reduction in weight so as not to be needing to factor in the central core if there is one. EG 1M = 200gm, so if the weight drops by 50gm it's 1M x 50/200 = .25M and it it drops by 1Kg it's 1M x 1000/200 = 5M Basically what Gary said. |
dugimodo (138) | ||
| 1410277 | 2015-10-21 17:57:00 | Looks like it's sorted but wouldn't it be easier to just measure how much was taken off at the time rather than calculate it after the fact ? . That's what I said. Son is inventory controller. Sorting out systems.......the workers don't make a note of how much is used each time is why. He said it would be nice if they did. He is supposed to have scales, still waiting for them after 5 months - plus the rolls of whatever it is are rather large, bit of a pain to weigh them... Anyway, he was happy with the calcs user found. Thanks people. |
pctek (84) | ||
| 1410278 | 2015-10-21 22:18:00 | Tell the workers to note down in a book how much they use, with threats of no pudding if they don't. | Agent_24 (57) | ||
| 1 | |||||