Hello,(adsbygoogle = window.adsbygoogle || []).push({});

Consider a cylindrical region (length dr, end area dA) at a distance r from the center of the sun

Density =ρ(r)

Volume = Length x area = dr.dA (How is the formula for volume of a cylinder works here?)

Mass= Density x Volume = ρ(r).dr.dA

Now, computing F(grav) = -G.m(r).dm/r^2.......we get F(grav)=-g(r)ρ(r)drdA. I understand up to that.

But the net pressure equation shows:

F(press)=(P(r+dr))- P(r))dA)

Can you please explain me how the above equation arrives?

Thanks

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Hydrostatic equilibrium of a cylindrical area

**Physics Forums - The Fusion of Science and Community**