Something in my brain has gone horribly wrong

  • Thread starter Thread starter Saladsamurai
  • Start date Start date
  • Tags Tags
    Brain
AI Thread Summary
The discussion revolves around confusion regarding the relationship between linear measurements and area calculations. A user struggles to understand why the area of a cube with a side length of 0.6m results in 0.36m², which seems counterintuitive compared to larger measurements. The key clarification is that when comparing dimensions, one must recognize that area (in square units) cannot be directly compared to linear measurements (in single units). A user explains that for any positive number less than 1, squaring it results in a smaller value, reinforcing the concept that dimensions and their squared counterparts are fundamentally different. The conversation emphasizes the importance of understanding units and the mathematical principles behind them.
Saladsamurai
Messages
3,009
Reaction score
7
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
 
Physics news on Phys.org
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).
 
Back
Top