Thursday, July 30, 2009

I have a Geology question I don't understand. Please Help.?

Suppose you are given three maps, A, B, and C (each 17.5 inches long by 13.5 inches wide). Map A has a scale of 1:62,500; map B a scale of 1:125,000: and a map C a scale of 1:250,000.





Which map represents the greatest area?





Which map represents the smallest ares?








How much area is shown on B compared to that shown on A?





Which map shows the greatest enlargement?





Detail?





I need to understand this!!!!!!!!!!!!!!!!!





* 13 minutes ago


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How do I do it?

I have a Geology question I don't understand. Please Help.?
Map A scale is 1:62,500


Map B scale is 1:125,000


Map C scale is 1:250,000





Imagine you are flying overhead in a plane. The bigger the scale (Map C), the farther away the plane is, the more range your eyes can cover, but less detail. The smaller the scale (Map A), the closer the plane is to the ground; you see a smaller extent, but more detail, such as lakes appear larger.





The scale itself is a pure ratio, which means any measured distance on map A is 62,500 times larger in real life. If a distance is measured as 1cm on the paper of map A (1:62,500 scale), then the actual distance is:





1cm : 62,500cm or 625 metres.





Same for B and C, except on B 1cm on the paper is:


1cm : 125000cm or 1250 metres





and on C, 1cm on paper is:


1cm : 250,000cm or 2500 metres.





As for area, Map B covers 4 times the area of A, and map C cover 4 times the area of B, thus 16 times the area of A.





This is really a geography question, not a geology question.
Reply:Hi. Multiply the scale by the sides. Ignore the units. 250,000 x 17.5 equals the miles across that side (or kilometers or lightyears or what ever the units are). Any help?
Reply:I don't give answers to obvious homework questions, but I'll give you a hint.





Look at the scale - the numbers are a ratio. 1:62,500 means a line one inch long on the map would be 62,500 inches long in real life.





Now look at the other scales, and work them out, and compare them. You should be able to figure out which one covers the most area.
Reply:The scales you are looking at are called ratio scales. All you really need to understand is this.





1:125,000 scale means that 1 of ANY UNIT of measurement on THAT MAP is equal to 125,000 of THOSE SAME UNITS on the ground.





1:62,500 scale means that 1 of ANY UNIT of measurement on THAT MAP is equal to 62,500 of THOSE SAME UNITS on the ground.





...and so on








The scale is dependent upon the actual size of the map for that scale. You have probably seen a bar scale used on some maps. The bar scale is the only one that holds true if the map is resized on something like a copy machine.





In other words if you were to reduce the physical size of the maps that you have then the original stated ratio scale would no longer be valid.





You should be able to figure out which represents the largest area etc from what I told you above.
Reply:It's quite simple if you think about it : just take the scale of the map times the number of inches wide, and it is obvious that the map with the '1 : 250,000' scale has the most area. That basically means that 'every 1 inch equals 250,000 mi/km/m', whatever. So, let's just say it's meters. If 1 inch on that map equals 250,000 meters, and on another map, 1 inch equals 125,000 meters, it stands to reason that the map where 1 inch equals 250,000 meters will have more area.
Reply:A smallest area.


B twice as much as A


C greatest enlargement.





Not sure if thats correct, may be reversed.
Reply:Hold it! Are you a student and if so don't you think it is time you learnt to be a self-motivated learner and a hardworking one at that?
Reply:* Greatest area is represented by the largest scale - C


The smallest is then A.





In A, each inch of map = 62,000 inches of ground - about 0.99 miles. therefore, A is17.5 x 62,500 in. by 13.5 x 62,500 in. or 17.3 miles by 13.3mi - 230 sq. mi.





likewise, B is 17.5 x 125,000 in. by 13.5 x 125,000 in. or 34.5 miles by 26.6 mi - 918 sq. mi.





The greatest enlargement is the smallest scale.
Reply:The 1:### tells you how many meters/feet or miles/kilometers per inch. The more they show per inch, the more the map shows if they are all of equal size. 1:smallest# covers the least amount of area, 1:largest# shows the greatest mount of area. Try to figure it out from there.
Reply:C, A, 200%, A. when asking about detail, the map showing the most enlarged area would probably have the most detail.


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