Answer:
D. The velocity components at any point are found from the first partial derivatives of the stream function at the given point
Step-by-step explanation:
The stream function can be used to plot the streamlines of the flow and find the velocity. For two-dimensional flow the velocity components can be calculated in Cartesian coordinates by u = −∂ψ/∂y and v = ∂ψ/∂x,
where u and v are the velocity vectors (components) in the x and y directions, respectively, ψ is the stream function.
From the above, the velocity components at any point are found from the first partial derivatives of the stream function at the given point.