4.9. example. show that if the velocity potential of an irotational fluid motion is =v cosê, where g, 0, v) are the spherical polar co-ordinates of any point, t

4.9. Example. Show that if the velocity potential of an irotational fluid motion is =v cosê, where G, 0, v) are the spherical polar co-ordinates of any point, the lines of flow lie on the surface r = k sin 8, k being a constant.