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Katpea
Sep15-04, 09:26 AM
: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!!

Doc Al
Sep15-04, 10:02 AM
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))

joyful55
Sep15-04, 10:46 AM
We need batter graphics. I'm having a hard time reading equations while trying to decipher the notations.

K.J.Healey
Sep15-04, 11:11 AM
: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.