Задача 20567.

One end of the cylindrical tube length of 30 cm and a radius R = 1 cm is filled with air and closed by a stopper. At the other end of the tube is slowly slid plunger. When moving the piston 10 cm tube flies. Find the friction force F plug on the wall of the tube at the time of departure. Atmospheric pressure is normal.

Detailed solution shorthand terms, formulas, laws used in the decision, the withdrawal of the calculation formula and the response.
If you have any questions to address, please. I´ll try to help.