code: def convert_stress_to_mass(q, width, length, gravity):
      
      mass = q * width * length / gravity
      return mass
docs: Converts a foundation stress to an equivalent mass.
  
      :param q: applied stress [Pa]
      :param width: foundation width [m]
      :param length: foundation length [m]
      :param gravity: applied gravitational acceleration [m/s2]
      :return: