35. Girya mass m = 400 g, suspended by the helical spring stiffness k = 40 N / m, is lowered into the oil. The drag coefficient r for this system is 0.5 kg / s. At the upper end of the spring effect the driving force that varies according to the law F = cosωt, N. Determine: 1) the amplitude of the forced oscillations if the frequency of the driving force is less than half the natural frequency; 2) the frequency of the driving force, in which the maximum amplitude of the forced oscillations; 3) the resonance amplitude.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)