Toy model of the outflow deceleration. Top panel: radial velocity of the H₂ as a function of distance from the centre along the ionisation cone. The dashed grey line represents the simple description given in Eq. (1) and Fig. 12. The solid blue line is a toy model described in Sect. 6.2, illustrating that this trajectory can be qualitatively assigned to a combination of the increasing gravitational potential and mass-loading. Bottom panel: characteristic spatial trajectory of a cloud described by the toy model, where the black circles indicate 0.5 Myr intervals. Initially the motion is radially outwards, but as the cloud decelerates the momentum imparted by mass-loading diverts it to tangential motion.