Show that the  latex1  component of the momentum equation in *fluid a* and *fluid b* simplifies to $\dfrac{\mathrm{d}^2 w_a}{\mathrm{d} y^2}=0 latex11 \dfrac{\mathrm{d}^2 w_b}{\mathrm{d} y^2}=0 latex20 w_a=0 latex11 w_b=0$.