PROBLEMS: An SDF system is excited by a sinusoidal force. At resonance the amplitude of displacement was measured to be 5 cm. At an exciting frequency of one-tenth the natural frequency of the system, the displacement amplitude was measured to be 0.5 cm. Estimate the damping ratio of the system.

Determine the reactions at A and E when the angle a = 30°. (image from Beer et al. 2010) 500 N 200 mm B 200 mm 30 E 150 mm 200 mm

Solve for determinacy and stability: А. В. B.

A prismatic fixed beam, modelled with a total lumped-mass of 20 kg as a single degree of freedom (SDOF) system is shown in figure. 5 m B 3 m The beam has a uniform flexural rigidity of 3240 kNm². The time period (in seconds, rounded off to two decimal places) of the vibration is .....