For steady isentropic flow,

1) show that you can use the continuity and linear momentum equations to form the area-velocity relation below and then

2)Discuss what it means for the area-velocity relation when M < 1 (nearly incompressible) versus M > 1 (compressible).

( 1 -(u/c)^2)* (1/u)*(du/dz) = (-1/A)*(dA/dz) where c, the speed of sound, is c^2 = (p/)_s. The Mach number M is defined as M = u/c.