Rearranging an equation for pressure

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The discussion revolves around rearranging the equation for pressure at the Earth's center, P = 2(pi*G/3)*ρ2 R2, to solve for R. The initial attempt incorrectly suggested R = 2(pi*G/3P)*ρ2 square rooted. The correct approach involves isolating R2 as R2 = 3P/(2 pi G ρ2) and then taking the square root to find R. A participant noted that the error stemmed from misinterpreting the division, leading to confusion in the rearrangement process. Clarity in mathematical notation and graphics was also highlighted as a need for better understanding.
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:cry:

I'm having big problems rearranging the following equation which calculates the pressure at the centre of Earth, to find R:

P = 2(pi*G/3)*ρ2 R2

Logically to me it would be:

R = 2(pi*G/3P)*ρ2 square rooted (but I'm pretty certain this isn't right!)

I've spent ages trying to sort it out and have resorted to randomly placing the figures in an attempt to find R (radius of the Earth which is known already)!

If anyone could help me sort it out in my head so that I can then rearrange the equation it would be much appreciated!
 
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Starting with:
P = 2(pi*G/3)*ρ2 R2
Isolate R2:
R2 = 3P/(2 pi G ρ2)
Now take the square root:
R = 1/ρ sqrt(3P/(2 pi G))
 
Last edited:
We need batter graphics. I'm having a hard time reading equations while trying to decipher the notations.
 
Katpea said:
:cry:

I'm having big problems rearranging the following equation which calculates the pressure at the centre of Earth, to find R:

P = 2(pi*G/3)*ρ2 R2

Logically to me it would be:

R = 2(pi*G/3P)*ρ2 square rooted (but I'm pretty certain this isn't right!)

I've spent ages trying to sort it out and have resorted to randomly placing the figures in an attempt to find R (radius of the Earth which is known already)!

If anyone could help me sort it out in my head so that I can then rearrange the equation it would be much appreciated!

What you did was on the left you should have gotten (1/R) not R, because you divided. Thats where you went wrong.
 

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