Suppose I have a cylinder tank with **R** radius and height **h**, and water filled with water up to the level **h**. There is a vertical rectangular slot on the surface with sizes **h** x 1 cm. There is only gravitation, no air resistance etc.

[![enter image description here][1]][1]

Obviously, a jet flowing from the small hole will have parabolic trajectory. But I want to define, what shape has the water flowing from the slot. 
I assume that vertical slope is like aligned holes with no distance betwwn them. Will the shape be like rectangular triangle with 45 degrees angles (like on 1st picture below) or it will have parabolic shape (like on 2nd picture below)?

[![Pic. 1][2]][2]

[![Pic.2][3]][3]

  [1]: https://i.sstatic.net/uE9Az.png
  [2]: https://i.sstatic.net/Z1flt.png
  [3]: https://i.sstatic.net/g3mM0.png