Question : Which parameters influence the dimension of the water column and its pinch-off time ?

Description : Here we have a 'force game' between inertia and gravity : From A to E inertia is predominant and so the water can rise (column). At the point F, we have an equilibrium between gravity and inertia. By the point G, gravity is becoming predominant on inertia and the column is ready to collapse . Only a little quantity of water stays on the disk (which is representing the cat's tongue) here on the point H.

Variables : Here, H is the final height of the disk. The pinch-off time refers to the moment when the water column loses contact with the glass disk. Umax is the maximal speed the disk achieves during the ascent. Fr is the ratio between the time the column takes to collapse and the time it takes to ascend. Here, the value Fr = 0.6 informs us that the column fell more quickly than it rose.

Next question : What can we deduce from the results of this model ? Specifically, when should mouth closure happen in order to maximize water intake ?

Fig 2 Tabs:

Graphing technique : Here, kinematics refers to the figures that plot the position of the tongue's tip of the cat over time.

Question: How does the position of the tongue during the lapping and its velocity change through time ?

Results: Figure A shows the position of the tongue for multiple cycles of the lapping process over 3 seconds. Figure B shows one cycle of the lapping process and plots the speed of the tongue. The tongue first accelerates and then drops to the surface of the water with decreasing velocity. Then it accelerates as it comes back up, and finally slows down as it enters the mouth.

Next question: How could we create a physical model replicating this process in order to assess the importance of different parameters for water intake ?