Something in my brain has gone horribly wrong

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Homework Help Overview

The discussion revolves around a physics problem involving the comparison of area and volume of a cube with a side length of 0.6 meters. The original poster expresses confusion regarding why the area and volume calculations yield results that seem counterintuitive when compared to the side length.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the relationship between dimensions and their respective units, questioning how area and volume can be less than the linear dimensions they derive from. Some suggest that the confusion stems from comparing different types of measurements (length vs. area).

Discussion Status

Several participants have offered insights into the nature of dimensional analysis and the implications of squaring and cubing numbers less than one. The discussion is ongoing, with participants attempting to clarify the original poster's confusion without reaching a definitive conclusion.

Contextual Notes

There is a noted emphasis on understanding the implications of unit conversion and dimensionality, with some participants suggesting visual aids to assist in comprehension. The original poster's emotional response indicates a struggle with the conceptual framework rather than a lack of mathematical ability.

Saladsamurai
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This is an extremely easy concept that for some reason is destroying my life right now.

It just came up in a physics problem that I posted elsewhere.

I have a cube of side length .6m So the area of one side is (.6)^2=
.36m^2

This does not agree with me. If it were of side length 6 then A=6^2=36.

This makes sense. 36>6. But .36<.6

Same with volume 6^3=216>6...but .6^3=.216<.6

what gives? What the hell is wrong with me/this?

Casey
 
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It's just the units that you're using. If you think of a cube of sides 60cm, then the area of one side would be 3600cm^2. Now, converting into metres; 1m^2=(100cm)*(100cm)=10,000cm^2, so 3600cm^2=3600/10000 m^2=0.36m^2.
 
Maybe I need to sleep on it, but I still don't see how the number of units squared can be less than the number of units in 1 dimension.
 
...maybe I see it now...darn, now I have NO idea what is wrong in my physics problem

Casey
 
It seems your question can be reduced to a problem with accepting that for all positive n, n > 1 => n2 > n and n < 1 => n2 < n.

Does restating your confusion in the above terms help clear some fog?
 
You are trying to compare .6m a length to .36m2 an area. This is an apples to oranges comparison, there is no way that a length can be greater then, less then, or even equal to a length.

If you would take the time to draw a picture, I bet you will quickly agree that square .6m on a side is about 1/3 of a square 1m on a side.
 
Last edited:
Remember, when you square it, your units also get squared. So basically before when it only took 100 cm for 1 m, now it takes 10,000 cm^2 for 1m^2.
 
Gokul43201 said:
It seems your question can be reduced to a problem with accepting that for all positive n, n > 1 => n2 > n and n < 1 => n2 < n.

Does restating your confusion in the above terms help clear some fog?

Yeah. I kid got beef with that too. I am not sure why yet...but I do.
Did I just say got beef?

Casey
 
Multiplying a number with another number that is less than 1 yields a number less than the first.
 
  • #10
Have you looked at a graph of y= x2 lately? For x< 1, it is below the line y= x. For x> 1, it is above. Of course, the curve and line cross at (0,0) and (1,1).
 

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