code: def ballistic_limit(h, a):
      """calculate ballistic limit
  
      Inputs:
        - h = thickness in (unknown) units
        - a = obliquity in (unknown) units
  
      Outputs:
        - v_bl = velocity (ballistic limit) in (unknown) units"""
      # h = x[0] * 25.4 * 1e-3
      # a = x[1] * pi/180.0
      Ho = 0.5794
      s = 1.4004
      n = 0.4482
      return Ho * (h / cos(a) ** n) ** s
  
label_desc: Use image node_id 1 for calling a global function with example usage: ballistic_limit(h, a) and returns: unknown