Okay, here's the question: A jet of incompressible fluid emerges from a horizontal channel into an environment of the same fluid. The momentum of the jet at the exit of the channel is measured to be M. The exit momentum is the source of a downstream flow which spreads gradually with distance. The fluid outside the jet flow is at rest. Use the Bernoulli equation to determine the axial (x) pressure beyond the boundary of the jet flow. How can that result, and the properties of the boundary layer equations be used to determine the axial pressure gradient inside the jet? So there's the question. I'm not really sure where to start. Any help would be much appreciated. Thanks!