PVC is indeed never clear. Apparently maple syrup has a density of 1.37, so that would narrow it down. If it's clear, however, I would say PETE.CPScienceDude wrote:I'm curious as to how you guys differentiate between PETE and PVC. When it gets down to those 2 it gets kinda dicey. I know PETE is always clear, and on the CB sheet that the people before me made it said that PVC is never clear. I looked it up, though, and I found a lot of conflicting information about if PVC can be clear or not. For the sake of this, assume that you are given a hard, clear plastic that sinks in all the solutions. You get it between PVC and PETE. Where do you go from there?\
EDIT: No burn test results or common uses were given either.
Crime Busters B
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jimmy-bond
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Re: Crime Busters B
PCHS, HI '21 | CWRU, OH '25
Code(16), DD(40), FQ(39),4&6(36), WQ(27)
CriB(26), DP (11), FF(1), MM(14), P&P(6)
CriB(36), DD(35), FF(2), MM(20)
Re: Crime Busters B
I'm doing some quick notes before regionals and I have a very important question about fibers!
All the information that I've found thus far has shown me how to ID fibers with burn tests, but I've been told by some people that there won't be burn tests happening at the event. Is that true? If so, how do I ID fibers without burning them?
All the information that I've found thus far has shown me how to ID fibers with burn tests, but I've been told by some people that there won't be burn tests happening at the event. Is that true? If so, how do I ID fibers without burning them?
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amk578
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Re: Crime Busters B
Whether or not burn tests are happening is up to the specific tournament, i.e. you can't always rely on just burn tests happening. If you won't be conducting burn tests, there are either two things happening. One, the test will give you a description of WHAT would happen when it burns and you would ID it from there or two, you simply have to look at the sample under a microscope and compare signifying features to ID the fiber.utumn wrote:I'm doing some quick notes before regionals and I have a very important question about fibers!
All the information that I've found thus far has shown me how to ID fibers with burn tests, but I've been told by some people that there won't be burn tests happening at the event. Is that true? If so, how do I ID fibers without burning them?
I'd say practice by looking at pictures online, like look up "cotton microscope view" or test it under your own microscopes.
2018 - Anatomy, Crime Busters, & Road 2019 - Anatomy, Disease, Heredity, & Road 2020 - Anatomy, DGenes, Disease, Forensics, Ping Pong Parachute, & Protein Modeling
Re: Crime Busters B
Was wondering how you can determine the speed of a vehicle based on its tire treads. I've already gotten the info for shoe prints, but I'm having trouble for the tire treads. Would it just be skid marks?
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CPScienceDude
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Re: Crime Busters B
I’ve never seen something like that on a test before, but maybe if there’s distortion in the tracks? I’m really not sure though.utumn wrote:Was wondering how you can determine the speed of a vehicle based on its tire treads. I've already gotten the info for shoe prints, but I'm having trouble for the tire treads. Would it just be skid marks?
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starfruit
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Re: Crime Busters B
Depending on the information given in the question, these videos might help-
https://www.youtube.com/watch?v=dKCw0cfrvD8
https://www.youtube.com/watch?v=d8nPlBKiaUM
https://www.youtube.com/watch?v=dKCw0cfrvD8
https://www.youtube.com/watch?v=d8nPlBKiaUM
code/forensics/it's about time
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Ocelot1912
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Re: Crime Busters B
Competition is soon, and I was wondering if you are allowed to touch the powders. Any replies are appreciated!
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SHASO2018
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Re: Crime Busters B
Out of curiosity, when did it change to 5 pages? When I was in Division B we were allowed to have a binder full.
R.I.P Region 15
Idk-2018
I'm getting too old for this
Idk-2018
I'm getting too old for this
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CPScienceDude
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Re: Crime Busters B
Yup, you're allowed to touch them.Ocelot1912 wrote:Competition is soon, and I was wondering if you are allowed to touch the powders. Any replies are appreciated!
Its actually down to one now, I'm not really sure when it changed, but it was 5 last year,SHASO2018 wrote:Out of curiosity, when did it change to 5 pages? When I was in Division B we were allowed to have a binder full.
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Crimesolver
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Re: Crime Busters B
wait wat I thought that was illegalCPScienceDude wrote: Yup, you're allowed to touch them.
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