General Questions

[daan]

I have a question: Does anybody know how to correctly use the subjunctive mood?

()

I'm guessing that I don't.

Yes. The solid explosive is designed to expel a certain amount of gas, which will dissipate into the atmosphere through the fibre mesh of the bag. I suppose if you assumed the cabin was completely airtight and no-one opened the doors, then maybe no.

Thank you for a serious answer to my serious question. What are airbags filled with? Is it lighter than air?

"Per Ardua ad Astra"

Is that about a Vauxhall advert?

 

[Sage]

What is it?

http://en.wikipedia.org/wiki/Subjunctive

You've been reading "The English Language: Notes from an American to a Scotsman."

Next up on the GTPlanet Learning Channel, "Per Ardua ad Astra", a series of aeronautical lectures delivered to breezeblocks by a Mexican Horned Pit Viper.

 

[Danoff]

Thank you for a serious answer to my serious question. What are airbags filled with? Is it lighter than air?

If it's lighter than air, that would actually cause the car to get heavier after the airbags deployed, because the gas would escape and be replaced by air - which is heavier.

 

[Venari]

Thank you for a serious answer to my serious question. What are airbags filled with? Is it lighter than air?

I think that there is a misconception at work here.

Airbags immediately deflate. They have huge vent holes in them. They are expanding as the occupant rushes towards them, it's the explosive gas moving backwards (in carline) which literally blows the occupant backwards, not a 'bounce' off a rubber balloon type bag. The film industry misleads you.

Imagine the sound of an unsilenced gun going off, and someone inflating a huge thick nylon weave balloon and popping it about as fast as you can sneeze. That's an airbag deployment.



And this is part of a Firefighter training video. This is why A) Firefighters cut the battery, then wait before getting you out... and B) why they are just damned heroes anyhow.



The dust you see in both shots is mostly fine powdered glass (silicates) a combustion product of the explosion. Since we're here and you're interested, let's go into detail.

The expanding gas is nitrogen, formed (typically) from sodium trinitride (or azide) and potassium nitrate, ignited electrically.

2NaN³ > 2Na + 3N²

The sodium metal dust produced then reacts with the potassium nitrate...

10Na + 2KNO³ > K²O + 5Na²O + N²

... and the potassium and sodium oxides are reduced to something safer by using something like silicon dioxide to form silicates - glass dust.

Sodium Azide is actually pretty nasty stuff, there are moves afoot to make something safer - but I have been out of the loop for a while on airbags. (I used to work as an engineer in seats with airbags.)

 

[Barracuda]

What phone should I get?

My RAZR finally craped out on me. All I get is a white screen now, and if I do finally get a screen, it's distorted in some weird way. The phone is quite amazing strength wise though. During this malfunctioning period, Ive become quite frustrated with it and thrown it around quite a lot. Ive even whipped it across a large room at full force and when it hit the wall, the only thing that happened is the battery came out.

As for a new phone, I'm looking for something that's not too bulky (considering the RAZR is quite skinny), looks good, is not that expensive, and is available with Verizon.

I myself am considering the enV (or whatever its called) because my cousin has one and they look quite nice, though they are pretty bulky.

Any suggestions would be appreciated.

 

[Metar]

Add me to the list of searchers. My aging Nokia is falling apart...

 

[wfooshee]

Is escape velocity the absolute speed that any craft exiting the atmosphere must attain? Or, can a parasite aircraft possibly exit the gravitational pull of the Earth at under 20,000km/h, while travelling at a relatively low angle of attack?

Sorry, I should have rephrased it...

Nothing like dropping back a couple of weeks, huh? I just got back from my trip to Jupiter, though, and there's no Internet service there.

Escape velocity has nothing to do with leaving the atmosphere. A craft that could remain powered could exit the atmosphere at a walking speed if it wanted to.

Escape velocity is the speed an (unpowered) object must reach for its trajectory to not return to the object it's escaping from. Less speed, it falls back eventually. More, and it reaches an area where some other gravitional field takes precedence, like it goes into orbit around the sun rather than the Earth.

Any particular planet will have a given escape velocity. Big planet, lotsa gravity, higher escape velocity.

Note that the escape velocity for getting to the moon is less than the escape velocity for getting to Mars. To get to the moon, you must get to the point that the moon's gravity field is stronger than the Earth's, so you "fall" towards the moon. To get to Mars, you must escape the Earth/Moon system as a whole. To get outside the solar system, you must reach an even greater velocity, to get out of the sun's gravity well.

This all applies to unpowered (ballistic) flight. Once the rocket motors stop, the craft is just a bullet, guided by gravity and gravity alone.

If we could make a craft that remains under power indefinitely, then there's no such thing as escape velocity. It would just fly out at whatever speed it needed, riding its motors rather than the gravity fields. The term escape velocity is a ballistic term.

Now, if all you're wanting to do is get to orbit, that's a much smaller figure, depending on how high you want to be in orbit. Higher orbits require lower speeds, but take more energy to reach. What's cool, and is the main reason we have such good computers these days (because NASA had to do these calculations back in the 60s) is that to reach a higher orbit, which requires a lower speed, you have to go faster. To reach a lower orbit, which requires a faster speed, you have to slow down.

Lastly, if all you want to do is lob a bomb at your enemies, you don't even need that much speed. That's a sub-orbital trajectory, no different than a big cannon shot.

 

[superberkut]

Suddenly I understand it! Thank you! (and to the rest of you who answered it; it reinforced my knowledge)

So, flight attitudes aren't the biggest factor? I was thinking that the North American X-15 could even break Earth's gravitational pull at a slow ascent rate at about 110,000 feet.

 

[Danoff]

Lastly, if all you want to do is lob a bomb at your enemies, you don't even need that much speed. That's a sub-orbital trajectory, no different than a big cannon shot.

Or Spaceship 1.

So, flight attitudes aren't the biggest factor? I was thinking that the North American X-15 could even break Earth's gravitational pull at a slow ascent rate at about 110,000 feet.

What do you mean by "break Earth's gravitational pull"? You mean head off into interplanetary space? Because that takes a hell of a lot of energy. If you mean obtaining orbit, that also takes a hell of a lot of energy. If you mean touching the edge of space, that's possible - but that's by no means "breaking" Earth's gravity.

 

[wfooshee]

The X-15 was fast, but not orbital fast, maybe a bit less than one-third fast enough on its best day. They did zoom up ballistically, though, and reached near-space altitudes.

 

[kikie]

What is the difference between college and university?

 

[Diego440]

AFAIK, in the US, during the old days, a University had various master's degree programs, while colleges had none or one. After a while, the number increased to around five, so more than five master's degrees was automatically a university.

Nowadays it's just a matter of which sounds better with the college name. The college I went to is called Canisius College, and in mid 1999 they reached a certain number of available master's degrees, and had the opportunity to change the name to Canisius University, but because it had been a college since 1870, they decided to keep it that way.

Traditionally, Universities are much bigger than colleges, and in certain cases, universities were public, while colleges were private... but again, none of those really qualify anymore.

 

[Famine]

What is the difference between college and university?

In the UK only Universities can award degrees. Colleges typically cater for 16-18 students - but some subsidiaries of universities are also called "College" (though the University is the degree-awarding institution).

 

[wfooshee]

In the US, a college offers a 4-year bachelor program, a junior college the first 2 years. A community college may carry some higher classes than the 2 years, also. Junior and community also offer trade-school type certifications. A university is a collection of colleges (school of business, school of engineering, etc.) and offers post-graduate degrees as well as bachelor's, and may be more research-oriented than a simple college.

 

[Megasoft Office]

What is the difference between college and university?

Here's an answer of useful guidance: Universities have a habit of being archaic. They'll often bank their appeal to prospective students on their history and reputation. College, on the other hand, is often very concise education that provides you with readily usable skillsets and experience. Neither is 'better' than the other, although the recent trend has seen a shift towards experience rather than the overpopulated market of degree-equipped academia. You'd want to graduate with specialized expertise in specific fields of study instead of a lofty degree loosely tied to your desired industry.

It's theory versus practice.

 

[UnoMOTO]

What phone should I get?

This is the phone for you if you want a RAZR like phone that actually works.

Model : VX8700

Sleek Music Phone
A shiny new addition to the LG handset lineup, the VX8700 will satisfy your craving for serious style with its ultra-thin shape, sleek metal finish, and mirror-like screen. This super sexy clamshell also features V CAST for music and video, Bluetooth® capabilities, a 2.0 megapixel camera & camcorder, and a microSD™ memory port for storage.

 

[superberkut]

What do you mean by "break Earth's gravitational pull"? You mean head off into interplanetary space? Because that takes a hell of a lot of energy. If you mean obtaining orbit, that also takes a hell of a lot of energy. If you mean touching the edge of space, that's possible - but that's by no means "breaking" Earth's gravity.

I see. I guess I mean in orbit, then. But, the airframe of the X-15 should be able to survive interplanetary flight, if not rapid descent. If the MiG-31 could do it, I suppose...

 

[nk4e]

Here's an answer of useful guidance: Universities have a habit of being archaic. They'll often bank their appeal to prospective students on their history and reputation. College, on the other hand, is often very concise education that provides you with readily usable skillsets and experience. Neither is 'better' than the other, although the recent trend has seen a shift towards experience rather than the overpopulated market of degree-equipped academia. You'd want to graduate with specialized expertise in specific fields of study instead of a lofty degree loosely tied to your desired industry.

It's theory versus practice.

Universities= ((somewhat of a view))Party animals/sometimes serious

College(s)= (( IMO))Stressed environment to get into those universities / sometimes party animals

Colleges do provide a transfer to the Universities for a Bachelor's degree or a Master's degree in a certain study but they mostly are limited to a AA or a AS degree as Megasoft pointed out

 

[Submerged]

In the UK only Universities can award degrees. Colleges typically cater for 16-18 students - but some subsidiaries of universities are also called "College" (though the University is the degree-awarding institution).

Just to put a spanner in the works, there can be "polytechnics" of education. However it is actually almost completely phased out in Britain due to the government desire for 50% of the population to have a degree-standard education. Polytechnics were almost Universities as they did provide further education after A levels, but were not quite able to have degrees and master courses. To get around that, polytechnics would offer HND courses which basically meant that you were at a polytechnic for one year, then moved to the university to finish off the other three years of the course. Or two, depending on the subject and how it was laid out.

Most of the polytechnics have now been converted into University due to the government target for Britain. Ironically, it's kinda leading to a situation of highly educated people who can research very well, but have next to no experience when they're 21 years old at the job that they want to do, whatever they may be. Note, i'm talking about business-type courses, not the scientific-based courses.

Well, that is what I understand of polytechnics anyway.

 

[Famine]

Just to put a spanner in the works, there can be "polytechnics" of education. However it is actually almost completely phased out in Britain due to the government desire for 50% of the population to have a degree-standard education. Polytechnics were almost Universities as they did provide further education after A levels, but were not quite able to have degrees and master courses. To get around that, polytechnics would offer HND courses which basically meant that you were at a polytechnic for one year, then moved to the university to finish off the other three years of the course. Or two, depending on the subject and how it was laid out.

Most of the polytechnics have now been converted into University due to the government target for Britain. Ironically, it's kinda leading to a situation of highly educated people who can research very well, but have next to no experience when they're 21 years old at the job that they want to do, whatever they may be. Note, i'm talking about business-type courses, not the scientific-based courses.

Well, that is what I understand of polytechnics anyway.

There are no polytechnics remaining in the UK. Universities remain the only institutions permitted to award degrees.

 

[wfooshee]

Universities= ((somewhat of a view))Party animals/sometimes serious

College(s)= (( IMO))Stressed environment to get into those universities / sometimes party animals

Colleges do provide a transfer to the Universities for a Bachelor's degree or a Master's degree in a certain study but they mostly are limited to a AA or a AS degree as Megasoft pointed out

You're describing junior college or communitity college, not a "real" college. At least in the US.

 

[nk4e]

You're describing junior college or communitity college, not a "real" college. At least in the US.

I am in a junior College but I think of it as High school all over again. I even ask a few people the same question. But it seems universities take some sort of a deeper dedication and level. But who knows, I may be wrong. I have looked at my environment at the junior college and I just seem more stressed people because they want a better life in a fast degree- achieving area.Also I have a few friends that are in major universities that come back to junior college because either it is hard or that they have made a bad mistake during the semester. Maybe I looked at the wrong group of people. " All work and no play makes Jack a dull boy"
I stress about my studies alot though I have work and just small daily errands everyday.

 

[superberkut]

Why does 10mm of snow equal 1mm of liquid precipitation when measuring climate statistics?

 

[Rykon Zero]

Snow has a butt-load of air in it.

 

[kikie]

Another question.

How can I, if possible, find the origine of an email that has been sent to me (the location from where it has been sent)? I use Mozilla Thunderbird. Is it possible to see if an email has been sent from another location then the previous emails?

This question is legit because I've been getting emails from someone whom is probably trying to con me (maybe, I'm not sure yet).

This person is going to move to another city and is going to send me an email when this person has arrived. I want to see if this person has really moved to another city.

 

[Bram Turismo]

Here's mine:

- People always say that it's healthy to drink lots of water. However, the other day, I drank 3 litres of water between 8.20am-15.00pm. Suddenly, a friend of mine start talking about the "dangers of drinking too much water". So, can one drink too much? What'll happen if you indeed drink too much?

 

[SolidSnake15]

If you drink too much too quickly you can die. Happened to somebody in a contest to win a Nintendo Wii.

 

[Rykon Zero]

Yes, you can drink too much. If the water has some chemicals in it, you can get sick from those, or if you drink about 2 liters in 10 minutes, you'll die.
Edit: tree'd

 

[Metar]

From what I recall in an article, it causes something similar to reverse dehydration - the salt-concentration in your blood drops too far. I don't remember too well, though.

 

[Bram Turismo]

Yes, you can drink too much. If the water has some chemicals in it, you can get sick from those, or if you drink about 2 liters in 10 minutes, you'll die.

Cool

Let's try that