Navier Stokes?

mcfc

I need to answer this problem:
The interface between two media is positioned along the plane [latex]x_3=0[/latex]. Medium 1 is a Newtonian incompressible fluid which occupies the region [latex]x_3 \le 0[/latex].
i)assuming the velocity and pressure fields in the fluid are given, determine the traction(?) that medium 2 exerts onto the fluid along the interface.
ii)now assume that only the velocity field in the fluid is known and that medium 2 is an inviscid fluid under pressure [latex]p^{(2)}=P[/latex]. What is the fluid pressure at the interface?

Is this an application of the NS equations....I'm sorry for the vague question but I'm a little lost on how to approach the question...