Baba copra weighing 408 kg hits a pile driven into the ground. Determine the resistance of the soil and the duration of the impact, if it is known that with each impact the pile plunges into the soil to a depth of 5 cm, and the height of the pile driver is 1.5 m.

A detailed solution with a brief note of the condition, formulas and laws used in the solution, the derivation of the calculation formula and the answer.