Plastic Definition and 278 Threads

  1. K

    Positively charged plastic rod of length L

    Homework Statement The figure shows a positively charged plastic rod of length L = 2.40 m and uniform linear charge density 8.00×10-3 C/m. Setting V= 0 at infinity, find the electric potential at point P for d = 1.536 m. Homework Equations The Attempt at a Solution Alright, I...
  2. R

    What is the best plastic for injection molding with high gloss and flexibility?

    Looking for a flexible plastic, equivalent to TPE shore A 50-60. Finish to be similar to ABS or PC, which mean high gloss, polish finish; that can be injection molded. Can somebody recommend a plastic resin that meet those criteria? -robert
  3. H

    Solving Physics Assignment: Launching a Plastic Stirrer with Electricity

    Homework Statement Your physics assignment is to figure out a way to use electricity to launch a small 6.0-cm-long plastic drink stirrer. You decide that you'll charge the little plastic rod by rubbing it with fur, then hold it near a long, charged wire. When you let go, the electric force...
  4. E

    Comparing Momentum of Two Carts with Different Masses

    Hello there, I am having difficulty with this question: A 0.2 kg plastic cart (Cart a) and a 20 kg (Cart b) lead cart can both roll without friction on a horizontal surface. Equal forces are used to push the two carts forward for a distance of 1 m, starting from rest. Which cart has the...
  5. N

    An electron is shot directly away from a uniformly charged plastic sheet Find σ.

    Homework Statement In figure (a) below, an electron is shot directly away from a uniformly charged plastic sheet, at speed vs = 2.13 × 10^5 m/s. The sheet is nonconducting, flat, and very large. Figure (b) below gives the electron's vertical velocity component v versus time t until the return...
  6. F

    Angular Spread Of Blue and Red Light Through Plastic

    Homework Statement The index of refraction for blue light in plastic is 1.46 and for red light is 1.39. Determine the angular spread of the spectrum leaving the plastic block [presumably to air] for a beam of white light incident at angle of 45° to the plastic block.Homework Equations...
  7. M

    What is the Young's Modulus for Plastics and How Can I Find an Accurate Value?

    Young's Modulus for Plastic URGENT I was wondering what is the young's modulus for plastics because I am looking all over the internet and can't find anything? Its because in an experiment i calculated it to be 10.9GPa but i need to compare it to an actual value. Thanks
  8. M

    Transparency of water, glass and plastic materials

    What causes water and other similar transparent things to become transparent? Visible light can pass through transparent solid object like glass but can't pass through many opaque objects. What is the reason? Again when liquid water turns into ice it loses its transparency. I'll be very...
  9. T

    Accurately cutting shapes into a credit card sized pice of plastic

    As the title suggests, i have to make cuts in a piece of plastic about the same dimensions as a credit card. the shapes themselves are fairly simple, mostly triangles, with 4 quarter circles on the corners. the device i have in mind would be something which i guess looks like a mechanical...
  10. BobG

    Erasing Permanent Markers from Plastic Name Plaques

    So, students are supposed to write their name on the plastic name plaque using vis a vis markers. After the class, it should be a simple matter to wipe the names off with a paper towel and water. Except that, somehow, a Sharpie from the last class is placed in the vis a vis can and one of...
  11. T

    High tensile strength plastic pipes

    Hey all, I'm trying to make a cylindrical bonded magnet, but I need to compress it in a non magnetizable pipe capable up withstanding up to 10000 psi pressure, 1 cm or less in diameter. PVC only has a tensile rating of 7500 psi so it won't do. i would like to know what plastic(or any non...
  12. B

    Modeling Plastic Cup Physical Behavior

    I've noticed that plastic cups exhibit some interesting physical behavior. Some paper cups(maybe all actually, I'm not sure) have concave bottoms, and when the liquid in the cup gets high enough, the forces from simply raising the beverage from the table to my mouth create enough force to pop...
  13. L

    Help me A spinning blue plastic object made me sleepless.

    Help me!A spinning blue plastic object made me sleepless. I've seen the mit online vedio course Physics I: Classical Mechanics Lecture 21 Torques, Oscillating Bodies,near the end 44:19.There is a spinning blue plastic object,the teacher spun it, it revolved then it stoped,then it revolved...
  14. O

    I can taste the plastic I drink water from

    If the water stays in a plastic bottle for a while, I can taste the plastic in it. Plastic flavor. The taste is as it smells. Have any of you ever noticed this? Am I actually drinking plastic? I don't find this taste in glasses or ceramic or metal. But it's definitely in the plastic and it's...
  15. I

    Injection Molding Machines - Plastic Gears

    Hello, I need some help with the general very basic cost analysis of an injection molding machine and a mold for a particular part (Plastic Gear). For example, a Gear made out of Nylon plastic resin. The gear dimensions are roughly 2 cm diameter (20 teeth). Something like the black one...
  16. E

    Plastic analysis of a beam,virtual work?

    hI! I'm trying to understand here a little bit of plastic analyses,but i can understand in the page of the book bellow,why the work at the plastic hinge is equal to MPx2theta?why MP and not MA? can someone explain me this with some angle relation or trigonometrics? the second is why the...
  17. M

    Plastic Engine Block Cooled with liquid metal

    Is there any research done on plastic engine blocks or cannon barrels ? I interested in using plastics at high heat high pressure environments after learning some researchers cools 1600 degree plate to 80 degrees with potassium or sodium or exotic metallic liquids. I think it might be possible...
  18. R

    Predicting elastic and plastic wheel deformation

    I am trying to predict elastic wheel deformation. I am not quite sure how to do it. How might one approach the problem? Take a steel wheel: 6 in. diameter, 2 in. thick, with a contact force of 1000lbs E = 30,000,000 psi Poisson ratio: .27 Would one calculate this in finite layers...
  19. P

    Plastic on cable, UHF flashback prevention?

    On my mouse cable, there is a blob of plastic which coils the wire once around, I don't know what the material is that encompasses it. Someone said it was for to stop UHF flashback. What does this mean? I also have it on loads of electrical appliances.. Cheers Philip
  20. S

    Tolerance class for Plastic Gear

    Hi Guys, Can anybody advise me where to get chart for tolerance class of 11e28 and 10e28 for the plastic Gears?
  21. T

    Electricity and magnetism - planar symmetry question: plastic sheets

    Homework Statement Three plastic sheets that are large, parallel and uniformly charged are placed side-by-side. The electric field strength between sheets 1 and 2 is 2x105; the electric field strength between sheets 2 and 3 is 6x105. What is the ratio of the charge density on sheet 3 to that on...
  22. M

    Which Plastic for Slide Charts? PVC, PEC or ??

    PVC, PEC or ?? I am looking for some help in determining the appropriate type of plastic for my application. I am in the process of having a slide chart manufactured out of plastic. It was recommended that I use 0.024 inch thick clear PVC. The samples produced with the PVC were fine with...
  23. fluidistic

    Loss of mechanical energy in a plastic collision

    [FONT="Arial Black"][SIZE="4"]Hi all, Homework Statement I'm stupefied. In continuation to my last thread (https://www.physicsforums.com/showthread.php?t=277124), I wanted to see if any perfectly plastic collision would make the total mechanical energy of the system go down to a factor of...
  24. N

    Electric potential of a plastic rod

    A plastic rod has been bent into a circle of radius R=8.20cm. It has a charge Q1 = +4.20pC uniformly distributed along one-quarter of its circumference and a charge Q2 = -6Q1 uniformly distributed along the rest of circumference. With V=0 at infinity, what is the electric potential a) at the...
  25. D

    Effects of Severe Plastic Deformation

    Hello, I'm a bit confused here about this topic. I can't seem to find a proper book on it so reading loads of papers of try and get a grip on it. I had come to the understanding that the high tensile and yeild strength developed here was due to the subgrain/micrograin size and the partial...
  26. C

    Medical Is it safe to reuse plastic water bottles?

    Is it alright to reuse plastic water bottles or leave them out in the sun or heat before using them? My dear mother seems to think that it isn't alright but I am not sure why. Is there a more reliable source that answers this question than a first link off google...
  27. B

    Electric Field Plastic Rod Problem

    Hello: Can someone help with this? A long, thin, nonconducting plastic rod is bent into a circular loop that has radius a. Between the ends of the rod a short gap of length l, where l << a remains. A positive test charge of magnitude Q is evenly distributed on the loop. What's the...
  28. E

    Can shape memory alloys recover from plastic deformation?

    Hi, I want to learn that do atoms or crystals dislocate in the plastic deformation of metals.
  29. 8

    How do plastic bags damage the environment?

    i have been taught that plastic bags damage the environment because they take thousands of years to decompose. this is not an explanation though. why is it bad that they take ages to decompose? i guess animals get trapped in them and some plastics are toxic but it would seem easy to put the...
  30. J

    Plastic Bag Recycling: Costs, Disposal &amp; Pollution

    Take a look at this slide show: http://www.poconorecord.com/_flash/soundslides/20080505plasticbags/soundslider.swf "There's harsh economics behind There's harsh economics behind bag recycling: It costs $4,000 to bag recycling: It costs $4,000 to process and recycle 1 ton of plastic...
  31. M

    Plastic deformation, or just cracks?

    Hi everyone, I'm having a bit of difficulty interperting the results of an ANSYS model I'm currently running. This is of a small, thin piece of metal (0.018" in thickness, ~1"x1" length x width), that I am fixing at one end and displacing the other end ~0.015". Essentially this is a...
  32. E

    Differential Scanning Calorimetry on plastic

    Hi Is there anyone, that can explan why the melting and crystallization peak of a plastic don not have same position in DSC scan?
  33. Norman

    Medical Are BPA and Plastic Bottles Safe for Children?

    Hello all, As the father of an infant son and an avid user of plastic bottles, the news from Canada and the US concerning the safety of certain plastic containers for children (and adults) made me investigate what types of bottles are safe. A quote from the Today Show: Is that...
  34. P

    What is the Role of a Plastic Engineer in the Manufacturing Industry?

    Hello, What is Plastic Engineering? What Engineering major as a BS is similar to Plastic? I am thinking it would probably be Nuclear? I am just curious what Plastic Engr is. Thank you in advance.. Take care,
  35. 7

    How Is Electric Force Calculated on a Charged Plastic Stirrer Near a Wire?

    Homework Statement Your physics assignment is to figure out a way to use electricity to launch a small 6.0-cm-long plastic drink stirrer. You decide that you'll charge the little plastic rod by rubbing it with fur, then hold it near a long, charged wire. When you let go, the electric force...
  36. M

    What Happens When You Bend a Plastic Cup?

    I was drinking from a plastic cup today with some physics friends, and we noticed that when we bent the cup, a white patch of plastic would form there, and the plastic would not be transparent at that point anymore. We were baffled by this observation, and none of us could really explain what...
  37. W

    Magnetic Stripe Readers, Plastic Bag Trick?

    How do the magnetic stripe readers in credit/debit equipment work? I am more curious how placing the credit card inside a plastic bag then swiping it works? I see it all of the time out in the field and I don't understand it.
  38. E

    Clear plastic w slight elasticity

    Hi, I'm not so well informed on plastics and chemistry to them but I need help finding a plastic that will fit the purposes of my need and uses. I'm looking for a plastic that is clear and elastic(doesn't have to be very elastic), or is the word I'm looking for plasticity, I'm not really sure...
  39. Loren Booda

    Plastic Bridges: Practicality and Feasibility for Bridge Construction

    Is there any practicability for making bridges out of plastic?
  40. J

    Plastic thing that will spin only one way? Wtf?

    Plastic thing that will spin only one way!? Wtf? Has anyone a clue how this works? In the video, the guy demonstrates a piece of plastic that will spin only one way. Just look at the video, you will see what I mean. It's really impressive, and I must know how it works! It's at about 4...
  41. I

    Is Acrylic Plastic Hydrophobic?

    Homework Statement when it comes to determine if a material is hydrophobic or hydrophilic, from what I know it is determined by the nonpolar or polar properties of the molecule. water is polar which as there is no neutral electron balance between atoms and one side of H2O is negative charge...
  42. moe darklight

    Revolutionizing Electronics: The Plastic Conductor Discovery

    plastic conductor? I just tooned into the end of a segment on "daily planet" about this guy who found out a way to create a plastic conductor. He says it conducts electricity as well as a metal wire and is very light weight (and will literally change the world of electronics). Anyone have...
  43. R

    Plastic shopping bags polluting New York

    Should disposable plastic shopping bags be banned in New York - they get stuck in trees and all over the place? Wouldn't it be better for the environment if we were all made to bring our own reuseable bags to shops - just like we did years ago?
  44. Averagesupernova

    Using ABS Plastic Outdoors: Pros & Cons

    How well does ABS plastic stand up to the elements? Normally I would not choose this for outdoor use but I am unable to find the type of enclosure I want in anything except ABS.
  45. A

    How do you build a home-made speaker using magnets, plastic, coils, etc.?

    Our teacher wants us to construct a speaker that can provide sound (that can be heard from anywhere within the classroom) when connected to wires that are hooked up to some sort of device. I'm unsure of where to start and where to get the supplies. Since we are on the magnetism course, I know...
  46. C

    Problem: Plastic Covering One Slit in Double Slit Experiment

    Homework Statement A very thin sheet of plastic (n = 1.45) covers one slit of a double-slit apparatus illuminated by 570 nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic? Homework Equations Constructive...
  47. DaveC426913

    Locating a leak in high pressure water plastic plumbing

    My hottub has a leak in its high pressure plastic plumbing. I've replaced what parts I can but am having trouble locating the leak since I have to drain the tub completely to examine it. Can anyone suggest a dye or something that will allow me to locate the leak even after the water is...
  48. L

    RP material suggestion needed (strong plastic)

    I've been looking for some kind of strong transparent/translucent Silicone RTV to make some small strong plastic prototype parts. So far I've only found stuff like smooth-on, but there should be something stronger out there.. I think.. Does anyone know a material that would fit my need...
  49. A

    Plastic Flow/Fracture: Stress Components Impact

    Why is plastic flow promoted by large algebraic differences in the principal stress components, whereas fracture is promoted by a large algebraic sum of these stresses?
  50. V

    Cause of Plastic Container Deformation in Microwave Oven

    Greetings, Earlier this afternoon I managed to ruin a perfectly good plastic container in a microwave oven by unwittingly deforming it. I curious as to why it happened. All I did was warm it (and the chilli inside it) for about a minute with the lid firmly secure. I've been told this was a...
Back
Top