Now you have an integrable expression, although you must first divide both sides by p to get all the pressure terms on one side of the equation. Carry out the integration and use the fact that p=p_{0} at z=0 to determine the integration constant. Then solve for the pressure at height z. Your final result should be in the form p=p_{0} {\rm exp}( - z/z_{0}). Enter the value of z_0.

Express your answer in terms of some or all of the constants g, rho_0, and p_0.

dp =-gdz(p*rho_0/p_0)

I'm not sure what I am supposed to get as the answer... i integrated and got p=-gdz(.5p^2)(rho_0/p_0) but how do i get z_0?