---

step:
  - discretization:
      t: 20
      N: 40
      f_out: 4
    mechanics:
      dot_F: [x, 0,      0,
              0, 1.0e-3, 0,
              0, 0,      x]
      P: [0, x, x,
          x, x, x,
          x, x, 0]