The stream function is given by a. Find the velocity vector at (2,5) 4 = 2xy b. Determine the equation for the streamlines E. The velocity components of a two-dimensional potential flow are given by u = -2x, v = 2y Determine the velocity potential and the stream function and show them graphically. -. A doublet of strength A = 20 ft³/s is formed by a source located at a=10ft to the left of the y-axis (x=-a; y=0), and a sink located at 10 ft to the right of the y-axis (x=a; y=0). The free steam velocity is 10 ft/s. Determine the magnitude of the velocity at the point (15,15). -. Two sources located at y=0 and x=a, and x= -a. Based on the method of images show that this flow is symmetric with respect to the plane x=0. 5. A potential flow is created by two vortices. A clockwise vortex at (-a,0) and a counterclockwise vortex of equal strength at (a,0). a. Determine the stream function, and the velocity components for this flow b. Determine the pressure distribution at the plane of symmetry x=0.