Results 1 to 50 of 236
Thread: 1/2²
-
07-01-2011, 08:53 PM #1
1/2²
Is it immediately clear that
1/2/2 = 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 08:59 PM #2
-
07-01-2011, 09:03 PM #3
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 09:06 PM #4
Re: 1/2²
Why do you feel the need to explain it?
-
07-01-2011, 09:06 PM #5
Re: 1/2²
1/2 divided by 2 is the same as 1/2 divided by 2/1 as in 1/2/2/1
We then multiply the top and bottom by a special case of the number one being 1/2/1/2 which cancels out to 1/2²
But why do some people have a proble with this - what are they missing?Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 09:07 PM #6
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 09:11 PM #7
Re: 1/2²
Anything divided by 1 remains as is.
245/1 = 245
1/2/1/2 = 1/2/2 = 0.25
-
07-01-2011, 09:25 PM #8
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 09:26 PM #9
Re: 1/2²
Most younger techs have been tought maths in a slightly different way to pherhaps how we were taught
"BODMAS"
(1/2)/2
-
07-01-2011, 09:38 PM #10
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 09:40 PM #11
-
07-01-2011, 10:01 PM #12
Re: 1/2²
1/2+3 =????
-
07-01-2011, 10:12 PM #13
Re: 1/2²
I thought that ratios were signed with a colon ':' as in 2:1 etc. or is that the wrong math now-a-days?
Brian - Newton Abbot, Devon, UK
Retired March 2015
-
07-01-2011, 10:18 PM #14
-
07-01-2011, 10:18 PM #15
-
07-01-2011, 10:21 PM #16
-
07-01-2011, 10:21 PM #17
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 10:25 PM #18
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
07-01-2011, 10:54 PM #19
Re: 1/2²
I'd say thats a half. I think i'm more verbal that written in my thinking. Thats why these things like tests and exams give me trouble. Or i'm just stupid Who knows?
If i was being flippant i would say that '1/2' is empty of any inherent meaning, it only means what you think it does because that is what you have learnt and you haven't seen anything since that learning to make you question that knowledge.
I don't mind my dyslexia, in many ways its a blessing. I am quite good at 3D stuff so bending pipes to fit is easy for me, and if i can get a picture of them in my mind i find systems easy to fault find.
Jon
-
08-01-2011, 12:36 AM #20
Re: 1/2²
I use an RPN calculator, that saves a lot of greif.
I went to school to eat lunch then learnt more after that, by choice.
If I knew then what I knew now, that situation would be totally different, but I cannot change time. Bugger
-
08-01-2011, 05:46 AM #21
Re: 1/2²
e^(pi*i) + 1 = 0Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
-
08-01-2011, 05:53 AM #22
-
08-01-2011, 07:30 AM #23
Re: 1/2²
Don't know what they're on but i wouldn't mind some.
Remember we are here for a good time, not a long time.
Trust me i'm a Fridgy.
-
08-01-2011, 07:31 AM #24
Re: 1/2²
Ahhh now i see it's Franks Harvest Pale,,,,,,must be good.
Remember we are here for a good time, not a long time.
Trust me i'm a Fridgy.
-
08-01-2011, 12:19 PM #25
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 12:28 PM #26
Re: 1/2²
Would you agree that it means something like "If I have part of a whole I can tell roughly how much of the whole my part is if I cut the rest of the whole into pieces equal in size to the part I have"?
The "/" means "per" so I have 1 per 2 as in I have 1 of the 2 or 1 for every 2. If there are just 2 of them then I have half of them but if there are an unknown or variable amount of them then I will be entitled to a ratio of 1 for every 2. Whether it is a fraction or a ratio is is the same thing. Physics formula are ratios but they become fractions once the amounts are known.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 02:14 PM #27
Re: 1/2²
It's important to understand how we work with fractions if we want to talk of physical principles in terms of ratios...
What does this reduce to...
1/2/1/2/1/2
As in, for instance, when we have
kg m²/s²/N/m/s²/KOnly the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 02:24 PM #28
-
08-01-2011, 02:36 PM #29
Re: 1/2²
?????? Having read that I now think I'm dislexic also.
I think there is a fundamental error here. You've taken a simple concept, ie a fraction 1/2 and made it into an extremely complicated structure by your own method of description. I really don't think the fraction has any need to be extorted in such a way. Poor fraction.
simply 1/2 = one whole divided by 2 or did I miss a lesson? Maybe I need some Harvest Pale?Last edited by nevgee; 08-01-2011 at 02:39 PM.
Reality is an elusion created by alcohol deficiency. Quaff and enjoy. [Yorkshire, UK]
-
08-01-2011, 02:44 PM #30
Re: 1/2²
The topic goes a lot, lot deeper than Euler & pure beauty.
The diatribe on the continued fractions is rather esoteric & beautiful. It proves nothing & will lead to confusion. Better to retain only a numerator & denominator, with various combinations strung in series products - as per dimensional analysis theory.
It is easy to appear incredibly smart at others' expense, but this can be counter-productive in the long-run. If you really want to take on a challenge, try explanations of how the various RHVAC circuits work - & develop solid design rules for these. We can then all chip in along the way & this group effort can teach us all something.Last edited by desA; 08-01-2011 at 02:48 PM.
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
-
08-01-2011, 03:00 PM #31
Re: 1/2²
I'm trying to take that which appears esoteric or appears as meant to be esoteric and rather make it common place.
Consider this example... Specific heat capacity
kJ/kg/k
Why does it reduce to kJ/kg.K and not KJ.K/kg ??
I have answers to this question - I brought it up a few times with my HND students at Bath College. I thought it so important that I even invited the college's math lecturer in to the class on one occasion to discuss the matter with us. After that occasion the question wasn't fully answered but I am now happy that I have thought enough about it to be able to explain the difference to myself.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 03:37 PM #32
Re: 1/2²
DT you ask questions but you have a mightier than thou attitude..
You come over as somone who has taken it upon himself to educate others around you.
But........................
But you do not educate you talk down and undermine others.
You are obviously very educated and extremely inteligent but you come
across as a condicending pr*ck who has had a humour bypass.
You have taken it upon youself to make us better but
you have not asked us if we want your help.
Some of us are not very well educated and when an academic starts showing
off at how inteligent he is, others just put you in the w*nker box.
I have been watching your posts on here since you joined and I have tried to weigh you up...
But I can't, I can't weigh you up, you preach and talk down to people, you never realy offer any
constructive advise, you just spout on about how good you are.
Some engineers on here could not add 2 and 2 together but I would trust them
with a set of spanners and gauges, you would try to belittle them, just to make you look better.
I'm in two minds regarding you.....
Your a w*nker and you need to be filed in the w*nker box
OR
You might have a lot of usefull information and you might be of help to a lot of
good engineers and teach them, if you would only get off your soap box and stop preaching to us.
Now if you are a troll and a wind up merchant you have just won and I have
lost because I bit and mouthed back at you.....
If your a pr*ck then you'll continue as you are.
If you are a decent bloke you'll pull your head out of your arse and offer constructive advise in a way that helps.
coolrunnings
.Last edited by cool runings; 08-01-2011 at 03:45 PM.
-
08-01-2011, 04:04 PM #33
Re: 1/2²
I understand fractions and their use, its just that its like numbers are a foreign langauge that i don't know that well, so unlike normal talking where you don't have to think to comunicate, i have to really think sometimes just to do what others may regard as a simple calculation.
I think it was when prime numbers were being taught at school that things started to go wrong for me, we were taught that a prime number is only divisible by itself and 1, e.g. 7 is a prime number.
But to me and my litteral way of taking things 7 and 1 is 8, and i may be daft but i know 8 won't fit in 7....
Jon
-
08-01-2011, 04:04 PM #34
Re: 1/2²
To go from kJ/kg/K to kJ/kg.K we could say that we did the following
kJ/kg/K/1 was multiplied top and bottom by a special case of 1 being 1/K/1/K (1/K goes into 1/K once).
But then that invokes the question why not...
kJ/1/kg/1/K/1 which when subjected to the same treatment gives us kJ.K/kg.
One way we can look at it is to say that specific heat capacity kJ/kg.K just means that if you had 1kg of the substance then its enthalpy content would increase so many kJ per K temperature rise but at the same time if your substance were to rise in temperature by 1K then the enthalpy rise would be so many kJ for every kg of the substance you had. In which case it doesn't really make sense to think of it as kJ per kg per K but rather from the very outset to think of it as kJ per both kg and K at the same time.
But then we might look around at other examples of the layout and say that always where we have three levels to a fraction we actually have a numerator in fraction form and a denominator implicitly in fraction form which just needs the "over 1" or "/1" to be added beneath it to make explicit that when the numerator is a fraction so too must the denominator before transposing the whole arrangement.
How though does this view stand in regard to acceleration which does seem quite clearly to be m/s/s or meters per second per second as in Velocity per Second. It doesn't seem right to start off from the outset with meters per second second. I feel that m/s² is different from kJ/kg.K and if it is then in what way is it different?Last edited by DTLarca; 08-01-2011 at 04:33 PM.
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 04:17 PM #35
Re: 1/2²
I don't understand the relevance of prime numbers myself. I fell asleep just at the point where I read the words in your post above - now that I have woken up I hope to make a quick escape from any further consideration of them
I have limited mental capacity - so I spend most of my efforts eliminating what I think is not important - I tend only to discuss or get involved with discussions on stuff I know is very importantly relevant to what I do.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 04:47 PM #36
-
08-01-2011, 04:56 PM #37
Re: 1/2²
Where acceleration is m/s/s and so m/s/s/1 becoming m/s² after multiplying it by a special case of 1 being 1/s/1/s we can do the reverse for pressure as in N/m² which can become N/m/m as in Newton per meter per meter.
If the force (Newton) was created by 10kg of water which would be 10 x 9.81 = 98.1N was over an area of 1m x 2m then the pressure in Pascals or N/m² would be 98.1/(1x2) = 49N/m² (Pa).
We could just as easily have followed N/m/m as in 98.1/1/2 = 49Pa.
Here we can look at 98.1/1/2 as if it were (98.1/1) divided by 2 gives 49Pa or someone might say "No, I see 98 divided by 1/2 which is 196Pa".
The correct answer seems to always come about when we treat the top most fraction as a whole number and then the remaining lower value as the denominator and treat it, during superposition, as an implied fraction by adding and "over 1" to it.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 04:58 PM #38
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 05:28 PM #39
-
08-01-2011, 05:33 PM #40
Re: 1/2²
I thought 3 was the magic number
-
08-01-2011, 05:33 PM #41
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 05:40 PM #42
Re: 1/2²
Engineering Specialist - Cuprobraze, Nocolok, CD Technology
Rarefied Technologies ( SE Asia )
-
08-01-2011, 05:54 PM #43
Re: 1/2²
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 05:56 PM #44
Re: 1/2²
With probability there will be uncertainty.
Is not the case that an uncertainty principle states by precise inequalities that physical properties, cannot be simultaneously known to arbitrarily high precision.
meaning that it is impossible to determine with any great degree of accuracy or certainty.
Can you then be certain it is One? Or should it be one and a little bit, or one and a little less?Reality is an elusion created by alcohol deficiency. Quaff and enjoy. [Yorkshire, UK]
-
08-01-2011, 06:07 PM #45
Re: 1/2²
In quantum theory Heisenberg's uncertainty principle applies to concepts such as trying to determine at the same time both the position and velocity of a sub atomic particle or at the same time the energy and the time.
It is like trying to know at the same time the tone of a musical note the current amplitude of the emitted sound - you cannot know both at the same time because a tone is a series of waves not a point moment of a wave.
But when it comes to "probabilities" we define them ourselves - probabilities lie between 0 and 1 or in terms of induction between just above 0 and just below 1 but never 0 or 1. As in the proposition "The sun has risen everyday in all of known history therefore it will rise again tomorrow" is a probability which cannot be a perfect 1. And the probability that the sun will not rise tomorrow cannot be a perfect 0 - we just cannot be so certain.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 06:33 PM #46
-
08-01-2011, 07:08 PM #47
Re: 1/2²
Yes, I tend to agree - I am fluent with the index notation - it has its own questions that crop up every now and then like why is anything to the index 0 equal to 1. Because 2²/2² is also 2² x 2-² = 2²-² = 2° = 1
But look at it from this point of view. Picture yourself standing in front of a white board explaining acceleration on a velocity/time graph (Vfinal = at) and you are explaining that where velocity is meters traveled per second (m/s) acceleration is meters per second PER SECOND and you place that on the board as m/s/s so that the students can see that you mean precisely meters per second PER SECOND.
How does it help them to understand it, when they are your typical level 3 student who hardly understands what 5² means let alone what 5-² or 5^½ means, if you throw it up on the board in index notation - how are they to get a feel for what we are talking about?
When I went to college for my tech cert we had to have at least matric math and science. In the UK most students are doing fridge only because they were poor at math and science, not because those were their favorite subjects (very odd but true) and this is what my quest is about.Last edited by DTLarca; 08-01-2011 at 07:11 PM.
Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 07:56 PM #48
Re: 1/2²
I remember doing the motion equations at school .... we didn't know what was going on, it was given to us in formula and by experimentation and model work. I recall specifically that we would draw our results in graph form (x & y axis).
acceleration was noted as m/s2 not m/s/s .. pointless notation which can only confuse further.
During my eductational and working life I found that it is essential for an instructor to level themselves at their students intellect level, Then work up from there. Pre judging someone's knowledge skill and then writing them off as being "stupid" is not the way forward and doesn't come over as very professional iether. I'm sure a good educator worth his salt can find the way to impart their knowledge to a student in the form that the student will understand, without having to try and rewrite conventional standards.Reality is an elusion created by alcohol deficiency. Quaff and enjoy. [Yorkshire, UK]
-
08-01-2011, 08:12 PM #49
Re: 1/2²
I have found the m/s² form is either taken for granted as representing acceleration but rarely something a student can put into words explaining what is happening when something accelerates or it is just plain not understood.
I find that when we set that aside and instead go to talking about how the meters traveled per second are increased by so many meters per second every second, as in m/s/s, then eye's start to light up. Then the question after that is usually "ah, okay, that makes sense now - so then how is that related to m/s² ?" and this is then when we get to the reason this thread was started.Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.
-
08-01-2011, 08:33 PM #50
Re: 1/2²
There are a few things i find are helpful in learning new things.
One is believing i need to learn it, that the new knowledge will be useful to me.
For it to go in, it needs to be demostrated so i understand it, and for me to practice it and then become proficient.
I then need to use it regularily to keep it fresh in my mind.
I wonder if a lot of engineers are practicaly natured, and would benefit from real world examples of how these formulas are useful.
I can see how it would be frustrating to have to teach students who lack even the basics, sometimes i get fed up repairing things or bored with installation work but i try to remind myself that without this work i would not be able to earn a living