Car Tech: What are the pros and cons of plastic cars?
- 6/6/07 1:57 PM
plastic versus metal electric shock in cars
by searcher-alpha - 6/26/07 4:36 PM In reply to: Plastic Cars by enawnAs far as I remember my screwdriver and wire cutters have plastic grips to shield me from shocks !!!!
Rubber tires prevent lightning from grounding if it hits...
by Cooltruth - 6/8/07 10:24 PM In reply to: Plastic Cars by drummonrLightning may be more likely to hit a metal car than a plastic car but you're safe inside that car due to those rubber tires preventing the lightning from grounding. Lightning attracts to steel more than rubber or plastic. Chances are slim that your car is going to get struck by lightning even if you live somewhere with lots of thunder storms.
Sorry, not true.
by Andy77e - 6/9/07 12:42 PM In reply to: Rubber tires prevent lightning from grounding if it hits... by CooltruthI used to think the same thing, but it's not true. There was a video I watched in which a mini-van was nailed directly on top by a bolt of lighting. It was truely incredible. I had thought the same thing, that there is no way lighting would hit something on rubber insulator.
There was a test done with a metal car in a lighting generator, and the metal did absorb the power perfectly without hurting the occupant.
The theory behind the idea that a plastic car is less safe, is that even though the panels might be plastic, the frame still is metal, thus a bolt of lighting would penetrate the plastic to get to the metal frame. Of course between the two is the occupant. That's bad. But it's unclear if lighting would in fact penetrate the plastic or not. No test has been done on plastic cars.
Got one
by Andy77e - 6/9/07 1:49 PM In reply to: Sorry, not true. by Andy77eI found one video, but it wasn't the one I saw a few years back.
http://www.youtube.com/watch?v=lUUOdO6eEZA&mode=related&search=
Lighting?
by Kurt Saldutti - 6/9/07 1:46 PM In reply to: Plastic Cars by drummonrDoes that mean that Corvettes and semi truck tractors made of fiberglass are all just waiting to be zapped? I think not. The probability of being struck by lighting in a vehicle is just as great in any form or the other. The tin body is a better conductor than say a Saturn or Corvette etc.
rest at ease.
by batman823 - 6/11/07 7:04 AM In reply to: Plastic Cars by drummonrPlastic is a dialecrtic, not a conductor. It does not easily conduct electricity. Metal cars would be much more likely to be struck. Both cases are very unlikely. The metal in the car, if struck, would conduct more easily than anything else in the car. You and the passengers would be protected if you weren't in contact with any metal part of the car. Most of the time, you aren't touching anything connected to the frame.
The tires on dry road would provide insulation, and therefore not completing a circuit to ground. The lightning could strike and pass through the water and dirt to the ground. But either way lightning is much more likely to strike a building or a tree, they are usually much closer to the clouds than your car. So don't worry about being struck bu lightning.
tires dont insulate
by caffjunkie - 6/20/07 8:57 PM In reply to: rest at ease. by batman823contary to common sense, which says that the rubber should insulate, tires are designed so that they actually CONDUCT electricity. if they did not, then static would build itself up in the metal of a car due to the friction of the tires and the road, and we would look like we were driving on third rails because there would be constant discharge sparks.... this is the reason that it is not a requirement for hazmat tankers to carry grounding strips (the tires conduct the electricity back into the road).... the reason you are safe in a car during a lightning storm is that the lightining hits the metal frame of the car (cars still have metal frames, just plastic body panels, and would still act as a faraday cage for teh passengers) and gets conducted into the ground very easily due to the tires... it is a low profile lightning rod and channels the electricity back to where it should be.... and if you have a slim chance of being hit by lightning whilst you are standing still, then you have even a smaller chance of being hit by lighting while you are moving.... and i actually feel SAFER in a tiny car than i do in a huge one because the smaller car is infinitely more manouverable and had a much less chance of rolling over than a large SUV does
tires do insulate
by randomtask2005 - 6/20/07 10:10 PM In reply to: tires dont insulate by caffjunkieThe vulcanized rubber in tires are natural insulators. There is no question to this. Electricians wear insulated rubber or rubber composite gloves for a reason. The reason that tires conduct is that tires have embedded strips of metal in them that all them to hold the tire together at high speeds. Static charge only builds up on a car in dry weather, in which case, the cars static charge is bled off into you when you open the door. In a lightning storm, the total amperage and voltage is so massive that the gap between the tire and the road is not large enough to stop the electricity from jumping that gap. Lightning generating machines can do this at a distance of meters and they are only at a fraction of the power of lightning.
Sprictly speaking, the treads of your tires are only about 5/16 of an inch thick. Beyond that is a metal/plastic layered composite that allows the tires to stay in one peice. 5/16 isn't very big gap compared to the distance lightning travels to the ground. So in actuallity the lightning just overpowers the resistance of the tires.
tires
by wcoffey81 - 6/27/07 5:35 AM In reply to: tires do insulate by randomtask2005but it's the carbon black used in automotive tires that lets them act as a grounding agent. the more carbon black the better the ground. this fact always comes up in discussions about car fires at the gas pump being caused by static electricity
grounding system
by batman823 - 6/21/07 5:24 AM In reply to: tires dont insulate by caffjunkieYou make a good point about static. Static electricity works a little differently though. The first reply to your post is a good one. Any polymer is a dialectric. A balloon will not conduct electricity so why do you think tires will? They can both build up static electricity. But static doesn't need a conductor. If the tires create it on the road, it's not just going to magically conduct to the road. You can rub a balloon on your head and touch something else to get a shock. But you are proposing that if you rub the balloon on your head, the balloon and you will pass electricity back and forth. That doesn't happen, the static charge is built up. Electrically, you and the ballon are one thing with a negative charge. That doorknob is the object with the relative positive charge, otherwise known as 'ground'.
The thing about cars though, is that the negative side of the battery is connected to the frame at one point or another. If you want to give somebody a jump. You still have to connect the red cable to the pos post, but the neg cable can just be connected to the frame. This is important. This feature allows for static and other stray electricity(grounds and stuff like that) to be conducted and dealt with by the car's electrical system.
But as far as the tires go.... think about when somebody peels out. When they do so, you don't hear the sound of metal scraping, you hear the reverberation of the rubber. There is no metal touching the road, so it is, in fact, an insulator.
Lightning has struck a car or two, but it's rediculous to even consider that as a factor when buying a car. They are short and make poor conductors when compared to a tree or the lightning rod on that barn.
Tires do not easily conduct electricity. A 1/4" of the right polymer, that I work with, provides protection up to 12,000Volts. The reason a car and allow lightning to pass through it is the extremely high voltage. I'm sure the ball-park voltage could be easily found on google or something like that. But if you've seen a pic of a car struck by lightning, its tires have blown because the large amount of power going through them. The charge in lightning is so strong that it ionizes air to form a conductor. A little rubber isn't going to strike it. 5 feet of air is much more of an insulator than a car. I say 5 feet because a small sedan is 4-5 feet tall.
I agree with you about the small vs big car thing though. If nobody hits me, I'll probably never have an accident. I said probably for a reason, I'm not stupid and I realize an accident can happen at any time. My car is very unlikely to roll over and I'm a safe driver. The SUV is more top-heavy.
I just realized we're all being stupid for even arguing about this tire thing. One jack-o mentioned lightning on this forum, either because he's dumb or just trying how many people he can get with the hook and bait. I hope for his sake he's laughing about the people, like us, who take the bait and run with it.
Conduction, insolators and lighting oh my!
by Andy77e - 6/30/07 8:53 PM In reply to: grounding system by batman823This thread goes everywhere doesn't it. Alright, little physics here. This is going to be the short quick and dirty remedial course.
Every atom of any element has electrons orbiting them. There are several layers of electrons. The outer most layer of electrons is called the Valence band. The Valence band can have as many as 8 electrons. If the number of electrons is low, like only 1, it is a conductor because electrons can freely join the Valence band, and leave. If the number is high, like 8, then there is no place for an electron to join and move from.
How does an electron move on from the Valence band? When an electron absorbs enough energy, it can "move up" a band. Since it's in the outer most band, it moves on.
Here's the key, enough energy can cause electrons to move on from even insulators. So rubber my not conduct a 240 volt source, making it good to insulate an electrician, but a rubber tire is not likely to stop the multi-million volts of lighting.
But what really makes this whole chit chat really dumb, is we forgot that if lighting already over-comes the biggest insulator known as "air", then why do we think rubber tires is going to insulate a car that has at most a foot of air between the chassis and the ground below it? Lighting has no need to go through a tire, when it can jump from the metal frame of the car to the ground. As my sister would say... "DUH!"
it's been a while, I love physics
by batman823 - 7/2/07 5:05 AM In reply to: Conduction, insolators and lighting oh my! by Andy77eAt least you know a little about physics. I did, however, note that lightning overcomes air. You just put it pretty bluntly. Other factors are involved in the lottery-chance vehicle to lightning battle. If, for some rediculously unlikely reason your vehicle gets struck by lightning. The tires are much less of an insulator than the air, but with the added water w/imputities, that makes it even better. Cars have been struck by lightning, and the tires explode when they do. That's because of the intense electric current going through them. What is not true, is that they conduct because of the metal bands inside the radial layers of rubber.But electricity at that kind of voltage need not worry about a few measly little tires.
The air smells different in a thunderstorm. Do you know why? Instead of waiting to see if anybody will respond, I'll just say it. The difference in potential between the earth and the clouds, which causes the lightning, ionizes the air. The ions line up to turn the air from an insulator into a conductor. Your body works off of ionized substances. If you ever get the chance, drink de-ionized water. It has no flavor and it gives you the squirts. Fun joke to play on the fellow submariner.
I agree this little string is pretty dumb. The rediculous concern that your car is going to get struck by lightning makes me wonder about the other things they might be afraid of. That well-known rumor about lightning striking tall things is true. I think a car is much shorter than a lightning rod on a building or the tree. But maybe I need my eyes checked.
Oddly
by Andy77e - 7/2/07 9:10 AM In reply to: it's been a while, I love physics by batman823The few "car struck by lighting" videos on youtube, do not show the tires exploding. Nor did the test with the VW. A VW bug was hit by man made lighting, and the tires did not explode, nor was there any water involved. Oh well, just observations.
Remind me never to get a drink of water from you or a physicist.
Come on andy
by batman823 - 7/9/07 4:55 AM In reply to: Oddly by Andy77ewon't you please drink from the cup? I imagine you're very parched. Besides, I'm not on the submarine anymore. I don't have access to the de-ionizers anymore.
But the tire thing. Shoes do explode. The tires do, but not always as shown on the videos, explode because of the tire rapidly being heated to high temperatures. That means the air inside the tire heats up too. With the tire already being pressurized(especially in low profile tires) that causes the tire to pop. No two freak accidents are going to be the same, but that's just what I'd seen in videos in the late 90's.
Cars being energised in electrical storm or grounded but not
by chipper777 - 9/28/08 3:10 AM In reply to: tires dont insulate by caffjunkieWhen I was young and farm I used to get shocked by electric weed burner fence until I wore rubber boots. But when it rained and the boots were wet I got shocked really bad! So, my question is: In a car that you are traveling in during a electrical storm has hale pounding down on your car and the street is wet and rain pounding down on you, with electrical strikes really close, and the tires are wet, why would you likely not get shocked? I am not trying to be dumb, I am really concerned about this. Also there are a new invention of airless rubber vaned tires that may be used in future, and will they be a risk in electrical storm when street is wet?
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