The velocity potential for a certain inviscid flow field is \phiϕ = - (3x2y - y3), where \phi has the units of ft2/s when x and y are in feet. Determine the pressure difference (in psi) between the points (2, 3) and (4, 4), where the coordinates are in feet, if the fluid is water and elevation changes are negligible.

The power source in a certain welding setup generates 3500w that is transferred to the low carbon steel work with a heat transfer factor of 0.85. the melting factor in the operation is 0.45. a continuous fillet weld is to be made with a cross-sectional area of 23 mm2 determine the travel speed at which the welding can be accomplished.