Author Topic: Questions & Facts about Energy  (Read 11309 times)

Srusti.M

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Re: Swarup Uncle's opinions
« Reply #30 on: June 15, 2009, 11:36:07 AM »
Dear Srusti,

Are you sure paper has no volume?? Why do you think the photo paper feels differently from your scratch paper (even leaving the quality part)?? Do you think some kinds of papers are thicker than others?? (on another note I guess you were taught decimal units in maths? right?!)

Because you brought up a very good topic ?. So I will let you the answer the following questions for me and also enlighten ?greenery? instincts in me and hopefully to others:

1)      can you figure out the height of a standard A4 paper (I hope you know A4 print paper dimensions; the length and breadth are standard? you need to calculate the height)? If possible try to search for more than 1 method.

2)      Now calculate the (surface) area (of highest 2 surfaces) of A4 paper and volume of A4 paper. Follow the units closely :)

3)      Assume a tree gives 100 liters of raw material for paper. Of which 40% actually goes to preparing final paper as we see it. How much fraction of tree goes into one paper.

4)      Taking the assumption in 3, (1 tree= 100 liters of raw material); and say your entire school uses 100,000 papers, how many trees are cut for the functioning of one school day.

5)      Can you name a 2D object (trick question)

Of course no rush take as much time as you want.

 

On other note Srusti, what are you doing this summer, Are taking part in any out-door activity?? I am sure there several other high ?energy? things you should be doing this summer.

 

Dear all,

My intentions in previous thread was not to cross with any one of your opinions. I apologize if anyone felt that way. I think Resnick and halliday is no bible. And starting physics with units and dimensions is not the best way. All I said was it can be taken as a starting point. Regardless of what we need a starting point and than go from there? We can argue the correctness of that starting point. If the forum thinks it?s a wrong starting point, as always I am willing to step back.

 

The thing is if we think we learn each topic and go back to units for each topic; learning that topic needs us to analyse the dimensions of the terms. Now it will be a chicken and egg logic to teach physics concepts  first or dimensions first. Taking these into account and based on my understanding that units and dimensions is integral part and not a separate term in any physics concept as a starting point I took that path.

 

Personally sorry asterias garu, in my previous post I had no intention of keeping you in mind. When I referred to word ?us? I meant the general mindset of overlooking and more specifically I was referring to myself. If any other meaning was implicit in my previous post I apologize.

 

To dwarakanath garu, I agree there are several other methods. Regarding, ?Feel? of weight?.I guess we discussed and I am not sure I agree totally but it?s a all together different discussion. Not going into the details, usually the discussion on feel, subjectivity, intuitions, usually end in a cross roads, of one saying there are fundamental standards and other asking for definition, dimensions and units if they are fundamental? so to avoid further debates I will let you go ahead.

 

Also as I said no need to take my words in point blank. And mentioned earlier no text book is a bible or gita. I personally question the latter two also, but that?s a different story. I am a strong proponent that personal experiences and personal learning is the paramount. I said resnick and halliday because it?s a text book prescribed in major courses across the world. Also, as I mentioned before, I have very high respect for the educational system, I mean the educational curriculum; because the curriculum designing is a well research one taking the age, average intelligence of 50 centile with 3SD of kids, so that covering 99% of kids across the population (school and college).  When a big group of well experienced people regard that as a good course work, I will believe it. I assume it should be same in India too. But I am not sure. Again, I am referring to the educational curriculum, not the finances involved in it and other stupid politics influencing the educational organization. This is my personal opinion, others can have different opinion of course. This said, if the forum moderators have a different opinion and that what I wrote is just a contamination of a general educational policy that forum advocates I will gladly step back.  I personally would not want to get into those arguments on the correct standards as everyone can ideally visualize their own. Whenever I write this I don?t mind the concept being criticized, and similarly what ever I write is not intended personally against anyone? if its taken that way it?s a communication problem as I don?t have it in my mind and also it unnecessarily deviates any meaningful discussion (again depending on how we define meaningful).

 
Om sai ram

Swarup
-------------------------------------------
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Dwarakanath

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Re: Questions & Facts about Energy
« Reply #31 on: June 15, 2009, 12:49:52 PM »
Jai Sai Master!

The way its going on is terrific swarupgaru. I would request you to go ahead with it. When I said "feel" weight, I didnt mean it in that way (the subjective vs. objective) that we discussed earlier, but what I meant was that if we directly jump into units and dimensions, that is one way. If we look at weight (since it all started with force and energy) and see why and how it happens and then going on into stuff like "force implies certain direction" and "energy is work done either to move something or stopping it" and then going on into scalars and vectors and units, while in the mean time, we can go into what 'matter' is, and since srusti seems to know atoms, we can go ahead and talk about why some molecules are clumped more strongly than others and what forces are involved in it and then also into Gravity and gravitation.

It could also branch off into centripetal and centrifugal forces, etc. And making her think all the time about these things ALONG side understanding units and formulae is what I was talking about. Rather than jumping into stuff like "weight is mass pulled by gravity" (giving her answers), may be we should make a habbit in her to really look around the world with wonder, by making her think about every day things.. Which is what you are doing regarding the A4 and Apples and all.

All in all, I love the way its going on.. keep going!!

Jai Sai Master!!!

Asterias

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Re: Questions & Facts about Energy
« Reply #32 on: June 15, 2009, 03:28:23 PM »
Jai Sai Master !

Dear Swarupgaru

Quote
Whenever I write this I don?t mind the concept being criticized, and similarly what ever I write is not intended personally against anyone? if its taken that way it?s a communication problem as I don?t have it in my mind and also it unnecessarily deviates any meaningful discussion (again depending on how we define meaningful).

I have similar thoughts. I whole heartedly accept that the discussion is of paramount importance :)

My post was more geared towards the general thinking methodology rather than directed at any single person (Which are my personal opinions, open to contention - but not on this board !! ). On a personal note, glad to have a discussion on pure science (physics) after a year long of META physics !!!

Please carry on Swarup garu ...

Jai Sai Master !

sai_prince

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Re: Questions & Facts about Energy
« Reply #33 on: June 15, 2009, 08:34:50 PM »
Swarup garu,
I really appreciate the way you are making us think. Its informative even to "elders" :)
Your simple way of explaining on matter and energy is excellent. thanks much.
I am glad i stepped into a "meaningful" forum :)

Jai sai master


drbatana

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Re: Questions & Facts about Energy
« Reply #34 on: June 16, 2009, 09:56:25 AM »
Jai saimaster,

Dear all saibandhus,

I would like to join this discussion praying Master garu that I can discuss with out bias. The Words those attracted me to this discussion are Energy, Matter, Rasnik and Halliday. It reminds me of the days when I used to study with passion, not for just scoring in exams. Even though I was a biology student I loved physics and Rasnik and Halliday was the book I used to refer to for some interesting physics problems like the famous application of newton's third law for the cart and horse question. The way people are analyzing the the explanations was fantastic keep on going.

I would like to say only one thing for physics students that don't leave any part of the concept not understood. I mean to say understanding completely and logically means one should be able to see the principle in many examples.

Keep on going.

Jagadeesh.

Srusti.M

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Re: Questions & Facts about Energy
« Reply #35 on: June 20, 2009, 11:43:49 AM »
Uncle,

These are the answers for your questions.

Are you sure paper has no volume??

Yes uncle I'm sure paper has no volume.

Do you think some kinds of papers are thicker than others??

Yes, I think that some kinds of papers are thicker than others.

(on another note I guess you were taught decimal units in maths? right?!)

yes, we were taught decimal units in Math.

Here are the dimensions of A4 paper.

 A4 paper size is 210*297 in mm or 8.3*11.7 in inches.

1)      can you figure out the height of a standard A4 paper (I hope you know A4 print paper dimensions; the length and breadth are standard? you need to calculate the height)? If possible try to search for more than 1 method.

A4 paper doesn't have height, if it doesn't have height how will I calculate volume for it?? :)

2)      Now calculate the (surface) area (of highest 2 surfaces) of A4 paper and volume of A4 paper. Follow the units closely Smiley

Well, to get the area we need to do L*W. So we can do 210*297 or 8.3*11.7. The area is 62370 square mm. or 97.11 square inches .

To get the volume we need to do L*W*H, so the formula for A4 paper would be 297* (L) 210*(W) 0 (H) = 0. So A4 paper has no Volume.

3)      Assume a tree gives 100 liters of raw material for paper. Of which 40% actually goes to preparing final paper as we see it. How much fraction of tree goes into one paper.

To solve this problem, we need to know how many liters of raw material is used for making 1 piece of paper. If paper had volume, we can easily find out how many Liters of Raw Material will go into 1 piece of paper. I couldn't figure out more than this.
 
I simplified 40% and got 2/5 , because I know % means parts of a hundred. So 40% means the fraction 40/100 a nd if I simplify that by 10,  I get   4/10   and if I simplify that by 2, I get 2/5.  40% can also be equal to 0.40.
                                                           
                                                           

4)      Taking the assumption in 3, (1 tree= 100 liters of raw material); and say your entire school uses 100,000 papers, how many trees are cut for the functioning of one school day.

To answer this question I need to know what fraction of the tree is used for making 1 paper, which I don't. :)

5)      Can you name a 2D object (trick question)

Yes, I can name a 2-D object.


Please give me a hint atleast on the questions I didn't know.
__________________________________________________________

what is conversion?

conversion means to change into another, just like money. Like when we travel to different countries, we convert dollars into rupees, dollars into pounds, dollars into dinars, and so on. Sometimes we change 4 quarters into a dollar 100 pennies into a dollar, and so on.

When I look into these units,

Newton : The newton is the unit of force derived in the SI system; it is equal to the amount of force required to accelerate a mass of one kilogram at a rate of one metre per second per second.

Joule : The joule (symbol J) is the derived unit of energy in the International System of Units. It is the energy exerted by a force of one newton acting to move an object through a distance of one metre.

They are mainly talking about Mass, Length, Time. Why??

First I would like to know what is Mass?? What is Length?? What is Time??

I know a little about Mass and Length but I don't know exactly what time is. Like,

How come time repeats on an analog and digital clock??

Humans weren't on the Earth for as long as Earth started, but how can we tell that we are exactly in the 21st century??

Who discovered time??

When did time start??

How come when a year is over it never comes back again??

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once we say packet it becomes an object, right?

Object is considered matter

Any Mater should be defined with two terms, mass, and volume

Volume as you have said earlier is dependent on length

So light is energy defined with mass and movement in length

Movement or velocity (or as a rough word-speed)  has length and time in it

So again energy is dependent on mass and velocity

Other words energy has mass, length and time in it

Like you said, energy has mass, length and time in it. So logically Mass, Length, and Time are in everything. There is Energy in us so there is Mass, Length, and Time in us. Is it right??

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Now one more time  lets do it backwards again:

Energy has Mass. Length and Time (last senetence)

Volume has Length in it.

Anything with volume occupies some space

So energy has mass volume and time

Volume is space---So, Energy has space in it

Mass and volume are objects or matter---- so matter has energy

Asterias Annaya,

Now I know for sure that Space HAS energy.

So Swarup Uncle,

We have Matter,Mass,Length,and Tme in us. Because we have Energy in us. But do we have Space in us??
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Srusti.M

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Re: Swarup Uncle's opinions
« Reply #36 on: June 22, 2009, 06:20:02 AM »
Swarup wrote:

 

Dear Srusti,

Not bad for a first try. Lets do it one more time:

Answer the following question and apply to the 5 questions in my previous post.

 

1) say 5 people work in MacDonalds for 1 hr (with all 5 equally contributing) and make $ 25 together in 1 hr, how much does each one make?

2) Similarly say if we stack up 100 A4 papers and combined have height ?X? ; what would be the height of each paper.

 

Using these hints try solving the previous 5 questions again.

 

Regarding why do we use mass, length, time to describe (For now....lets think about time latter....)?.

First I would like to know your opinion, why do you think those are used. Now if you want a hint on how to analyze this question, can you please describe your science text book  for me. I don?t want to know whats in your text book :-) describe the textbook without opening it. Than try describing 3-4 different objects of your interest to me (may be your toys, playstation, anything).

 

Om sai ram

Swarup
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Dwarakanath

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Re: Questions & Facts about Energy
« Reply #37 on: June 23, 2009, 06:21:38 AM »
Dearest Srusti!

Great questions! (wink at swarupgaru for that Time question.. :D)

Anyways, let me put what Swarupgaru asked.

If a paper doesnt have height, why do a bunch of 100 papers have height?? why do books have volume if paper doesnt have volume?



Swarupgaru :

Your question about that 2d object got me thinking.. is there any 2d object in the universe??
The only thing i could think of is that only 'Surface' is 2d.. Any 'surface'. Its only mathematical, i guess. Other than that,  i dont know of any real object that is 2d. can there be any??

Jai Sai Master!!

Srusti.M

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Re: Questions & Facts about Energy
« Reply #38 on: June 23, 2009, 11:00:27 AM »
Quote
If a paper doesn't have height, why do a bunch of 100 papers have height?? why do books have volume if paper doesnt have volume?

Yes Annaya, igot the same question how come a 1 piece doesnt have height and 100 pieces have some height....and i got the answer that piece of paper has height but its so tiny, we cant measure it with ordinary measuring tools. just like we cant measure the weight of a drop of water but we can measure a bowl of water. we cant measure a grain of sand but measure a pile of sand, we cant measure a small tiny rock but we can measure huge big rock.



Swarup Uncle,

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1) say 5 people work in MacDonalds for 1 hr (with all 5 equally contributing) and make $ 25 together in 1 hr, how much does each one make?

Each person gets $5 dollars.

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2) Similarly say if we stack up 100 A4 papers and combined have height ?X? ; what would be the height of each paper.
But Uncle I need to know the volume to know the height right, and I to get the volume of the 100 papers I need to know the Height, I don't know neither the volume or height. I already know the area, but how can I get the volume from area??Area's formula is L*W and volume's is L*W*H so all we need to convert the area to volume is the H. What i am going to do is, tomorrow i'll go to  Officemax  and get 100a4 papers and measure the height of the 100 papers and finish the questions.

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using these hints try solving the previous 5 questions again.
I will do it soon.

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Regarding why do we use mass, length, time to describe (For now....lets think about time latter....)?.

First I would like to know your opinion, why do you think those are used.

 Uncle you described the Quantum Theory to me in the former post and in that you said that energy has Mass, Length, and Time in it.  And i've learned that energy is in everything, so if mass.length and time are in energy and energy is in everything, logically mass length and time are in everything.

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Now if you want a hint on how to analyze this question, can you please describe your science text book  for me. I don?t want to know whats in your text book :-) describe the textbook without opening it. Than try describing 3-4 different objects of your interest to me (may be your toys, playstation, anything).
please uncle No please.:)

my science text book is a rectangular prism.

it has a cover, spine, and back, it is colorful, It is bulky(800-900 pages), it has more than 3 pounds, it has about 1 1/2 inch height, it is 12 inches in length,

Than try describing 3-4 different objects of your interest to me (may be your toys, playstation, anything).

my stuffed animal(arjun) he is a dog, he wears sun glasses he is tan and brown color.

my bicycle: its purple, it has bell, has black handle bars, it has 23 inch wheels.

TV:  its rectangular prism, its black, flat, 50 inches diagonally,( why do we measure our tvs diagonally??), 43 inches length, 28 inches width.



"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

svelagal

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Re: Questions & Facts about Energy
« Reply #39 on: June 23, 2009, 09:15:55 PM »
Quote
Quote
If a paper doesn't have height, why do a bunch of 100 papers have height?? why do books have volume if paper doesnt have volume?

Yes Annaya, igot the same question how come a 1 piece doesnt have height and 100 pieces have some height....and i got the answer that piece of paper has height but its so tiny, we cant measure it with ordinary measuring tools. just like we cant measure the weight of a drop of water but we can measure a bowl of water. we cant measure a grain of sand but measure a pile of sand, we cant measure a small tiny rock but we can measure huge big rock.
I dont want to offend Swarup garu, but want to clarify my confusion also along with Srushti.
This seems to be little bit confusing :) . My take is if it is a paper ,it has no volume, but as a book definitely it has volume. 
I am thinking the reverse engineering may not be suited for all of the things, the general thought process of 100 papers means you are keeping 100 papers in a stack, if i spread each paper horizontally, again 100 papers wont have any height. 
It is a similar kind of think where if i know the meaning of a word, doesnot mean i know the meaning of each letter in it.  When you combine it has the meaning but if you see each letter, it wont give you the same meaning.
Please clarify

Quote
Now if you want a hint on how to analyze this question, can you please describe your science text book  for me. I don?t want to know whats in your text book :-) describe the textbook without opening it. Than try describing 3-4 different objects of your interest to me (may be your toys, playstation, anything).
please uncle No please.Smiley

my science text book is a rectangular prism.

it has a cover, spine, and back, it is colorful, It is bulky(800-900 pages), it has more than 3 pounds, it has about 1 1/2 inch height, it is 12 inches in length,


Good description :) I love it, but my question is why science book? may be swarup garu expecting some thing else when he is asking you to describe?


Quote
TV:  its rectangular prism, its black, flat, 50 inches diagonally,( why do we measure our tvs diagonally??), 43 inches length, 28 inches width.

I think it is a business technique to make people fool by saying 50 inches screen, as length and breadth of any rectangular is less than its diagonal.

Quote
Swarupgaru :

Your question about that 2d object got me thinking.. is there any 2d object in the universe??
The only thing i could think of is that only 'Surface' is 2d.. Any 'surface'. Its only mathematical, i guess. Other than that,  i dont know of any real object that is 2d. can there be any??

yes same feeling , but i doubt can we call Surface as an object ?

Please forgive me and guide me if i had posted any thing wrong.

OM SRI SAIRAM!

!!!Sarve janaa Sukinoo bhavantu!!!!
!!!Samasta sanmagalani bhavantu!!!

Srusti.M

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Re: Questions & Facts about Energy
« Reply #40 on: June 27, 2009, 08:59:20 AM »
Quote
Are you sure paper has no volume??

OK, OK  paper DOES have volume but it's height is so minute that we can't measure it with normal measuring tools.

Quote
1)      can you figure out the height of a standard A4 paper (I hope you know A4 print paper dimensions; the length and breadth are standard? you need to calculate the height)?

Uncle, we went to Office Depot but they didn't have any A4 papers. When we asked a "May I Help You" Person :) he said that most of the Office Depot Stores in the US carry the same thing, and that we need to order A4 papers, so that's why I didn't get A4 but only Letter size. The main idea is for me to get an idea of how volume works right?? So that's why I'm using Letter size paper here, Sorry. But I did measure the height of some Letter Size papers which are similar to A4 papers. A4 paper's dimensions are 8.3 in.*11.7 in. and Letter Size paper's dimensions are 8.5 in * 11 in. And the height that we got for most of the Letter Size papers are 2 Inches. But for one of the letter size papers I got 2.2 inches. Here is the list I made:

50 sheets, Glossy Photo Paper (Canon) - H is 1/2 in.
300 sheets, Color Laser Gloss (Hammermill) - H is 7 in.
500 sheets, Premium Multipurpose (Hammermill) - H is 2.2 in.
500 sheets, (Letter size) Copy Paper (Office Depot) - H is 2 in.
500 sheets, (Letter size) Laser Paper (Office Depot) - H is 2.2 in.
500 sheets, (Letter size) 35% Recycled Paper (Office Depot) - H is 2 in.
500 sheets, (Letter size) Multipurpose (Office Depot) - H is 2 in.
500 sheets, Astrobrights - H is 2.5 in.
500 sheets, Fine Linen Paper (25% cotton) - H is 2.8 in.
500 sheets, Pastels Plus (Xerox) - H is 2.2 in.


The height for 100 letter size Papers would be 0.4. Here's how I got that answer:

Lettersize Paper - 500 sheets (Ream) = 2 in.    (one Ream means 500 papers)
Height of 1 sheet is 2/500 = 0.004 in
Height of 100 sheets is 0.004 * 100 =0.4 in. (simplified)

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If possible try to search for more than 1 method.

What are the other possible methods, please let me know.

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2)      Now calculate the (surface) area (of highest 2 surfaces) of A4 paper and volume of A4 paper. Follow the units closely Smiley

Surface area is equal to Length * Width.

Length = 11 in.
Width = 8.5 in.

 Length * Width = 11 in. * 8.5 in.

Area = 93.5 sq. in.

Volume is equal to Length * Width * Height

11 in. * 8.5 in * 0.004 in.

Volume = 0.374 cu. in.

Quote
3)      Assume a tree gives 100 liters of raw material for paper. Of which 40% actually goes to preparing final paper as we see it. How much fraction of tree goes into one paper.

Volume of 1 paper = 0.374 cu. in.

As you said a tree gives 100 liters of raw material. And only 40% actually goes into paper. So 40 liters goes to paper.

To make 1 paper we need  0.374 cu. in. I converted these cu. in. into liters by using a formula that i found on the Internet.

0.374 cu.in. = 0.006128 liters

Fraction of tree used = 0.006128 / 40 = 0.0001532 / 1

0.0001532

Quote
4)      Taking the assumption in 3, (1 tree= 100 liters of raw material); and say your entire school uses 100,000 papers, how many trees are cut for the functioning of one school day.

1 tree gives - 100 liters of raw material

 0.006128 liters gives 1 paper

100 liters will give 100 / 0.006128 = 16,318.53 papers

So 100 liters (1 tree) will give 16,318.53 papers.

How many trees needed for 100,000 is 100,000 / 16,318.53 = 6.12

For the functioning of one school day a school needs 6.12 trees.(swarup uncle upto this part is the answer for your question)

For entire academic year a school need How many papers??

School academic year has 4 semesters, and one semester has 9 weeks and a week has 5 days.

So  4 * 9 = 36 * 5 = 180 days. A school academic year has 180 days.

So 180 days * 6.12 trees a day = 1101.6 trees
So for a entire school academic year we need 1102 Trees for paper.

There are 25 schools in our city. That means 1101.6 * 25 = 27,540 trees.

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5)      Can you name a 2D object (trick question)

Well, I don't think we can find a 2d object. Not in our Universe. Every single thing in our universe has some height, it could be 1 mm. or 0.5729105307257574801549583578 of an mm. Even how small it can be, height is still height. Our Universe itself is 3-D. How can there be 2-D objects in a 3-D object ?? 2-D objects are imaginary like the Equator or Prime Meridian. They are like guidelines. When I was in Kindergarten they would give me a wooden cube and ask me what it was. I would say square. And the teacher would say it is correct. We are taught like that at first since we are too young to understand about cube. See. 2-D objects are just like the Equator and Prime Meridian, guidelines, but they are imaginary.In art class, when we are trying to draw something we make light guidelines so we know where some of the body parts go like the eyes. But after we finish the drawing we erase the guidelines. That's how a 2-D object is. We use it as guideline for learning but after we learn we don't need them anymore. Like when we are learning about the cube they teach us that the cube is made up of 6 squares. After we learn about the cube, if the teachers ask us "What are the characteristics of the cube " we say that it has 6 faces,12 sides, etc. But we never say that a cube is 6 squares put together because that is a wrong answer. The "Square" like objects on the cube are called faces. The faces on the cube have some height too. If we slice 1 of the faces off, it will still have some height. Some houses have pyramids ( 3-D triangles) on top of their houses. But if we ask a 5 - 6 year old "what shape is that??" They will answer Triangle. But once they get older and move up to a higher grade, they will learn that those are NOT triangles but pyramids. In my opinion 2-D objects only exist in our Math Book, just like the Equator and Prime Meridian only exist in maps. So we can name them as imaginary objects.

Universe is a combination of Matter and Space. Matter has Mass. Mass is a combination of Atoms and Molecules. Atoms and Molecules occupy Space. That means that atoms and molecules SURE have Volume. Am i right??



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I know we calculate area for 2-D objects and Volume for 3-D objects, but what are they exactly??

When ever we measure Area we always put Square before the units. When we measure Volume we always put Cubic before the units. When I went to Lowe's Gardening Section for purchase Mulch  bags for our garden, i noticed that they measure the Bag in 3 different ways, Cubic Feet (Bag size), Square feet (Coverage area), and Depth (Height).

So Area means what it Covers or occupies, and Volume means what it contains in it. Am I right Uncle??

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but my question is why science book? may be swarup garu expecting some thing else when he is asking you to describe?


May be because he likes Science.
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Srusti.M

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Re: Swarup Uncle's opinions
« Reply #41 on: June 28, 2009, 01:47:50 AM »
Excellent Post Srusti!!! Loved reading each and every word you wrote. exactly what was in my mind.

I hope your post creates awareness in recycling things.

On a different note I was thinking if you can start (re-start) energy conservation thread (of course only my thought, if you agree). Which I think I saw some where on kids forum long back. We can have a new look at things in this thread.

Although I am not clear on how to go about with it, I want to see on that thread, facts and figures (reasonable assumptions are fine or rather would be warranted as needed). Instead of saying save this save that, we will put a scientific look . If you agree I will tell you more in my next post.

Swarup
Om sai ram
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Srusti.M

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Re: Questions & Facts about Energy
« Reply #42 on: June 28, 2009, 01:49:13 AM »
I will be glad to start a new thread on Energy Conservation. So you want me to start a whole new thread OR I can change the subject's name from Energy to Energy Conservation, since we are talking about 2 similar things OR we can continue in the exact same thread. I'll go with whatever option you pick.
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

Srusti.M

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Re: Swarup Uncle's opinions
« Reply #43 on: June 28, 2009, 01:50:23 AM »
I guess new thread is better, and we will focus completely on energy conservation in as scientific way as possible.

Swarup
Om sai ram
"We should not bother about a wish that Baba did not fulfill because we should believe that he did it for our own good. We need strong faith in Baba to believe that he does things for our own good."

sai_prince

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Re: Questions & Facts about Energy
« Reply #44 on: June 29, 2009, 06:04:23 PM »
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Are you sure paper has no volume??

OK, OK  paper DOES have volume but it's height is so minute that we can't measure it with normal measuring tools.

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1)      can you figure out the height of a standard A4 paper (I hope you know A4 print paper dimensions; the length and breadth are standard… you need to calculate the height)…

Uncle, we went to Office Depot but they didn't have any A4 papers. When we asked a "May I Help You" Person :) he said that most of the Office Depot Stores in the US carry the same thing, and that we need to order A4 papers, so that's why I didn't get A4 but only Letter size. The main idea is for me to get an idea of how volume works right?? So that's why I'm using Letter size paper here, Sorry. But I did measure the height of some Letter Size papers which are similar to A4 papers. A4 paper's dimensions are 8.3 in.*11.7 in. and Letter Size paper's dimensions are 8.5 in * 11 in. And the height that we got for most of the Letter Size papers are 2 Inches. But for one of the letter size papers I got 2.2 inches. Here is the list I made:

50 sheets, Glossy Photo Paper (Canon) - H is 1/2 in.
300 sheets, Color Laser Gloss (Hammermill) - H is 7 in.
500 sheets, Premium Multipurpose (Hammermill) - H is 2.2 in.
500 sheets, (Letter size) Copy Paper (Office Depot) - H is 2 in.
500 sheets, (Letter size) Laser Paper (Office Depot) - H is 2.2 in.
500 sheets, (Letter size) 35% Recycled Paper (Office Depot) - H is 2 in.
500 sheets, (Letter size) Multipurpose (Office Depot) - H is 2 in.
500 sheets, Astrobrights - H is 2.5 in.
500 sheets, Fine Linen Paper (25% cotton) - H is 2.8 in.
500 sheets, Pastels Plus (Xerox) - H is 2.2 in.


The height for 100 letter size Papers would be 0.4. Here's how I got that answer:

Lettersize Paper - 500 sheets (Ream) = 2 in.    (one Ream means 500 papers)
Height of 1 sheet is 2/500 = 0.004 in
Height of 100 sheets is 0.004 * 100 =0.4 in. (simplified)

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If possible try to search for more than 1 method.

What are the other possible methods, please let me know.

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2)      Now calculate the (surface) area (of highest 2 surfaces) of A4 paper and volume of A4 paper. Follow the units closely Smiley

Surface area is equal to Length * Width.

Length = 11 in.
Width = 8.5 in.

 Length * Width = 11 in. * 8.5 in.

Area = 93.5 sq. in.

Volume is equal to Length * Width * Height

11 in. * 8.5 in * 0.004 in.

Volume = 0.374 cu. in.

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3)      Assume a tree gives 100 liters of raw material for paper. Of which 40% actually goes to preparing final paper as we see it. How much fraction of tree goes into one paper.

Volume of 1 paper = 0.374 cu. in.

As you said a tree gives 100 liters of raw material. And only 40% actually goes into paper. So 40 liters goes to paper.

To make 1 paper we need  0.374 cu. in. I converted these cu. in. into liters by using a formula that i found on the Internet.

0.374 cu.in. = 0.006128 liters

Fraction of tree used = 0.006128 / 40 = 0.0001532 / 1

0.0001532

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4)      Taking the assumption in 3, (1 tree= 100 liters of raw material); and say your entire school uses 100,000 papers, how many trees are cut for the functioning of one school day.

1 tree gives - 100 liters of raw material

 0.006128 liters gives 1 paper

100 liters will give 100 / 0.006128 = 16,318.53 papers

So 100 liters (1 tree) will give 16,318.53 papers.

How many trees needed for 100,000 is 100,000 / 16,318.53 = 6.12

For the functioning of one school day a school needs 6.12 trees.(swarup uncle upto this part is the answer for your question)

For entire academic year a school need How many papers??

School academic year has 4 semesters, and one semester has 9 weeks and a week has 5 days.

So  4 * 9 = 36 * 5 = 180 days. A school academic year has 180 days.

So 180 days * 6.12 trees a day = 1101.6 trees
So for a entire school academic year we need 1102 Trees for paper.

There are 25 schools in our city. That means 1101.6 * 25 = 27,540 trees.

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5)      Can you name a 2D object (trick question)

Well, I don't think we can find a 2d object. Not in our Universe. Every single thing in our universe has some height, it could be 1 mm. or 0.5729105307257574801549583578 of an mm. Even how small it can be, height is still height. Our Universe itself is 3-D. How can there be 2-D objects in a 3-D object ?? 2-D objects are imaginary like the Equator or Prime Meridian. They are like guidelines. When I was in Kindergarten they would give me a wooden cube and ask me what it was. I would say square. And the teacher would say it is correct. We are taught like that at first since we are too young to understand about cube. See. 2-D objects are just like the Equator and Prime Meridian, guidelines, but they are imaginary.In art class, when we are trying to draw something we make light guidelines so we know where some of the body parts go like the eyes. But after we finish the drawing we erase the guidelines. That's how a 2-D object is. We use it as guideline for learning but after we learn we don't need them anymore. Like when we are learning about the cube they teach us that the cube is made up of 6 squares. After we learn about the cube, if the teachers ask us "What are the characteristics of the cube " we say that it has 6 faces,12 sides, etc. But we never say that a cube is 6 squares put together because that is a wrong answer. The "Square" like objects on the cube are called faces. The faces on the cube have some height too. If we slice 1 of the faces off, it will still have some height. Some houses have pyramids ( 3-D triangles) on top of their houses. But if we ask a 5 - 6 year old "what shape is that??" They will answer Triangle. But once they get older and move up to a higher grade, they will learn that those are NOT triangles but pyramids. In my opinion 2-D objects only exist in our Math Book, just like the Equator and Prime Meridian only exist in maps. So we can name them as imaginary objects.

Universe is a combination of Matter and Space. Matter has Mass. Mass is a combination of Atoms and Molecules. Atoms and Molecules occupy Space. That means that atoms and molecules SURE have Volume. Am i right??



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I know we calculate area for 2-D objects and Volume for 3-D objects, but what are they exactly??

When ever we measure Area we always put Square before the units. When we measure Volume we always put Cubic before the units. When I went to Lowe's Gardening Section for purchase Mulch  bags for our garden, i noticed that they measure the Bag in 3 different ways, Cubic Feet (Bag size), Square feet (Coverage area), and Depth (Height).

So Area means what it Covers or occupies, and Volume means what it contains in it. Am I right Uncle??

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but my question is why science book? may be swarup garu expecting some thing else when he is asking you to describe?


May be because he likes Science.


Very good post and I guess answersall our questions . I never realized that so many trees are cut for working of schools. Very enlightening

Jai sai master