While it is possible to solve this problem starting from calculating the pressure distribution and the force acting on the cylinder, it is much easier to start from writing down the energy conservation law.
Other than that:
– do not make the problem more difficult than it already is: neglect viscosity means the drag force is zero, and there is no turbulent drag, either (it would require a lot of time for the turbulent trace to develop!).
– please simplify your answer keeping in mind the given strong inequality; your answer should not contain any untaken integrals;
– this week’s hint is fairly subtle; more specific hint will be given next week.
Please submit the solution to this problem via e-mail to physcs.cup@gmail.com. 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.