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.

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)

If possible try to search for more than 1 method.

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

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.

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

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.

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??

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??

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.