What acceleration produces one gravity force?
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Fruitfrenzy
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Humus said:
While I am all for SI units in science, having speeds and distances using units of length and time that are big (kilometres, miles and hours as opposed to metres and seconds) gives you a much better idea of how long a journey is going to take.
Well my personal feeling is that SI units are a lot easier to work with in most cases. After 4 years of engineering education I cringe every time I am forced to do a English units problem as unit conversions are an absolute nightmare most of the time. How many people know what a Slug is or how to convert it...not many...I would much rather use kilograms. The base 10 system of SI is definately a good thing...but I don't think the US will change for a while (we officially are but it is never used in reality). I guess I should be thankful that the SI system is stressed in the courses and most professors won't put anything other than SI on exams.Fruitfrenzy said:
Kilometers/hour is fine with me. I just hate the English unit system, miles, pounds, etc etc.
Physicists dont really care though, one gets so used to converting between archaic systems its not even important, all you need is a reference point.
As a theorist, the first thing I do anyway, is to make all units dimensionless.
Physicists dont really care though, one gets so used to converting between archaic systems its not even important, all you need is a reference point.
As a theorist, the first thing I do anyway, is to make all units dimensionless.
HELL no. Going to do EE. I can't become a lawyer with a clean conscience, and a doctor is right out.Razor04 said:
Well EE isn't too bad...Comp E. is much worse according to my friends that are Comp. E's. They swear that they would never pick Comp. E. again if they did it all over. I must say I am quite happy being a Mech. E. though. Not too much physics involved there...but lots of statics and all. Finishing up the final design on my senior design project and I am ready to collapse...and finals start tomorrow. This blows...is it Friday yet?The Baron said:HELL no. Going to do EE. I can't become a lawyer with a clean conscience, and a doctor is right out.Razor04 said:
The problem with m/s on roadsigns is that medium long times are usually measured in hours, and 1h/1s isn't a power of ten. I'd say that it would have been best if we had done away with *all* non-power-of-ten units when the SI units were formed.
Get rid of those pesky hours/minutes/seconds, take the current definition of a second, multiply it with 24*60*60, and call it a day. Then strongly encourage everyone to give all times in decimal fractions of days.
"I'm off for lunch, I'll be back in 40md." (1md = 1 milli day)
"We'll start the morning meeting at 350 (md)."
"The new world record for 100m is 115µd."
A road sign could say 2.5 with an implied unit Mm/d. (Which would be the same as km/md.)
Only problem is that time measuring devices (clocks) usually holds much more affectionate (and monetary) value than other measuring devices. It's a lot harder to make people replace their clock with a metric clock, than to make someone replace a yard stick with a meter stick.
But the switch should have been done at the same time as when the other SI units were formed. Changing the units one at a time isn't a good idea. And now there's a lot of stuff with built in clocks that would make it a lot harder to do a quick swatch.
And it would need to be an official switch to make it work. If it's just some watch company that decide to make watches that show time in milli days, and tries to push their company name in the unit name, then it's a sure failure. (Making the time in sync over the world so that "350" means different times of the day in different places is also a no-no.)
PS
I just realized, the only SI unit that is in use in UK is the one I'd like to get rid of.
Get rid of those pesky hours/minutes/seconds, take the current definition of a second, multiply it with 24*60*60, and call it a day. Then strongly encourage everyone to give all times in decimal fractions of days.
"I'm off for lunch, I'll be back in 40md." (1md = 1 milli day)
"We'll start the morning meeting at 350 (md)."
"The new world record for 100m is 115µd."
A road sign could say 2.5 with an implied unit Mm/d. (Which would be the same as km/md.)
Only problem is that time measuring devices (clocks) usually holds much more affectionate (and monetary) value than other measuring devices. It's a lot harder to make people replace their clock with a metric clock, than to make someone replace a yard stick with a meter stick.
But the switch should have been done at the same time as when the other SI units were formed. Changing the units one at a time isn't a good idea. And now there's a lot of stuff with built in clocks that would make it a lot harder to do a quick swatch.
And it would need to be an official switch to make it work. If it's just some watch company that decide to make watches that show time in milli days, and tries to push their company name in the unit name, then it's a sure failure. (Making the time in sync over the world so that "350" means different times of the day in different places is also a no-no.)
PS
I just realized, the only SI unit that is in use in UK is the one I'd like to get rid of.
I like the old imperial system. The units may not work as well together in base 10 maths, but its unit sizes are very practical and useful quantities for people to work in.
Still, we'd have been better off going base 12 anyway. Then everything would be evenly divisible by 2, 3, and 4; which would be much more useful in real life than just 2 and 5.
Still, we'd have been better off going base 12 anyway. Then everything would be evenly divisible by 2, 3, and 4; which would be much more useful in real life than just 2 and 5.
Neeyik said:
That's simply because m/s is only used in science, and not in everyday's life. If you see it daily on road signs, you'd get a good sense of it very quickly. Heck, when I drove a car for the first time in the US, and the speedometer and road sign was in mph it felt odd for the first 30min or so, but then I got used to it. I got realtime feedback through my senses, which you don't get with you nose in a physics book with fancy numbers. Getting used to m/s would be a lot easier than getting used to a new currency.
Neeyik said:
The units are clearly defined and dependent on each other in clear ways. It also uses prefixes like kilo, mega etc. and not random multiples like 12 inches = 1 foot, 3 feet = 1 yard, 5280 feet = 1 mile etc.
Fruitfrenzy said:
Kilometres is fine. It's SI standard, meter with a kilo prefix. The problem though is that we use hours, rather than say kiloseconds in everyday's life. Had we used kiloseconds there wouldn't be a problem. But I guess it would be very hard to change the time system. Way harder than anything else. But a good start would be if US/Canada/(UK?) and everywhere else where they use 12 hour system changed to the 24 hour system that makes much more sense, zero based and one loop per day.
Legion said:The Baron said:HELL no. Going to do EE. I can't become a lawyer with a clean conscience, and a doctor is right out.Razor04 said:
you are aware that not all lawyers are criminal lawyers.
Rugor said:
That's part of it. The other parts:
1. I'd be expected to move to Pittsburgh, work for my grandfather's law firm or my uncle's law firm, and that wouldn't be too cool (for one, I don't want to live in Pittsburgh)
2. I don't think I'd enjoy it as much as, say, just about anything else.
But, I don't really know what else I would do. Not an artist or a musician (could be a pianist if I practiced, but, I don't like it nearly enough, and my parents are proof that you don't make money), definitely not up to being a doctor, and I dunno. EE interests me, at least at the moment, so what the hell.
Willmeister
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Yes, it will. SI is so superior to US Customary, it's not even funny. I'm also willing to bet that the US Customary unit system is a big part of why the US students do more poorly than other industrialized nations. The metric system is so easy to use, it's not even funny.
It's exactly like the switch over from Roman numerals to the Arabic/Indian number system. Such a huge boon to progress, it's almost immeasurable.
Willmeister
Newcomer
Ratios? wtf? Are you referring to derived units? US Customary has billions of bizarre ones. We're basically forced to use them and it's a total pain in the a** to convert from one base unit in US Customary to another base unit EVEN IN US Customary. You never really know if you've gotten it right unless you do it over and over. The only way you can make it any easier is by having tables, tables and more tables. With SI units, you're moving the decimal point.
Some of the units are no less "random" than imperial. Take the metre for example - it is defined as the distance travelled by an electromagnetic wave in a vacuum over a time interval of 1/299792458. Now where does that number come from? From the definition of electromagnetic wave propogation in a vacuum, of course, which is 1/(permeability multiplied by permittivity - vacuum for both)^1/2. Now take the values of the permeability = 4 x Pi x 10^-7 N/A^2 and the permittivity = 8.854187817 x 10^-12 F/m. How these numbers are less ridiculous than some of those used for imperial?Humus said:
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