A vertically positioned homogeneous rod weighing 7 kg and 1 m long can rotate around its upper end. A bullet weighing 5 g hit the lower end of the rod, stuck, as a result of which the rod deviated by an angle of 10 °. Assuming that the mass of the rod is concentrated at the lower end, find the initial velocity of the bullet.

A detailed solution with a brief note of the conditions, formulas and laws used in the solution, the derivation of the calculation formula and the answer.
If you have any questions about the solution, write. I try to help.