Japanese scientists have calculated the trajectory of the feces of the penguins and said rectal pressure required to start the Kal. The calculations showed that the closer of 1.34 meters to the penguins better not to approach — this flight distance is achieved if the nest is located on a two-meter stone. The solution of this problem, scientists have proposed for teaching the course of theoretical mechanics. A Preprint of the article published on the website arXiv.org.
Penguins a long time to hatch the eggs and some species spend up to 100 days. Not to get out the heated seats and leave the nest relatively clean, they shoot their feces for a short distance, which is approximately 40 centimeters, which is comparable to their growth. Moreover, penguins use their feces for arrangement of the territory of their colony, so they melt snow.
In 2003, researchers have used the accumulated observations to assess rectal pressure. They estimate it is between 10 and 60 kPa, and the viscosity of the faeces, as well as the size of the cloaca of penguins. However, in their work, physicists have used the model of the Hagen-Poiseuille’s only for movement by air and estimated the pressure using only the horizontal component of the trajectory
Physicist Hiroyuki Tajima (Tajima Hiroyuki) from Kochi University and a member of the aquarium of Fujisawa Katsurahama Fumiya (Fumiya Fujisawa) calculated the maximum distance of flight of penguins feces from a high pedestal, which corresponds to the elevated position of the nest. They also said the value of rectal pressure, given the movement of feces in the stomach in the field of action of gravity. In the new model of the gastrointestinal tract of penguin is considered as a cylinder with the lateral intestinal opening.
In the first approximation, scientists estimated the upper bound of the maximum distance of flight, neglecting air resistance. In this case, the equation of flight of a projectile launched at an angle to the horizon. At the aquarium of Katsurahama the average height of the stones in the cage for the penguins equal to 1.1 meters, at this altitude the maximum flight distance of faeces will amount to 1.03 meters at an angle to the horizon 21 degrees. And with a maximum height of stones two meters to the penguins better not to approach to a distance of 1.34 meters.