Problem 1 – Hint 2

Due to the given strong inequality, you can neglect the kinetic energy of the cylinder itself, as well as the kinetic energy of the water everywhere outside the narrow gap between the floor and the bottom of the cylinder. So, for the kinetic energy, you can keep only the kinetic energy of water inside the gap. (Of course, for a nice solution, you would still need to show that this approximation is valid.)

Please submit the solution to this problem via e-mail to The next hint for the Problem 1 will be published at 13:00 GMT, 4th December 2022, together with the next updates of the intermediate results.