The 6-kg uniform rod AC is attached to springs of constant k = 500 N/m at B and k = 620 N/m at C, which can act in tension or compression. If the end C of the rod is depressed slightly and released, determine (a) the frequency of vibration, (b) the amplitude of the motion of Point C, knowing that the maximum velocity of that point is 0.9 m/s.

Explain how they got d?

An automobile is modeled as a single-degree-of-freedom system vibrating in the vertical direction. It is driven along a road whose elevation varies sinusoidally. The distance from peak to valley () is 0.2 m and the distance along the road between the peaks is 35 m. If the natural frequency of the automobile is 2 Hz and the damping ratio of the shock absorbers is 0.15, determine the amplitude of vibration of the automobile at a speed of 60 km/hour. If the speed of the automobile is varied, find the most unfavorable speed for the passengers.

A uniform rod AB can rotate in a vertical plane about a horizontal axis at C located at a distance c above the mass center G of the rod. For small oscillations determine the value of c for which the frequency of the motion will be maximum.

A motor of mass M is supported by springs with an equivalent spring constant k The unbalance of its rotor is equivalent to a mass m located at a distance r from the axis of rotation. Show that when the angular velocity of the motor is wf, the amplitude of the motion of the motor is where

A 400-kg motor supported by four springs, each of constant 150 kN/m, and a dashpot of constant c = 6500 N·s/m is constrained to move vertically. Knowing that the unbalance of the rotor is equivalent to a 23-g mass located at a distance of 100 mm from the axis of rotation, determine for a speed of 800 rpm (a ) the amplitude of the fluctuating force transmitted to the foundation, (b ) the amplitude of the vertical motion of the motor.

A torsional pendulum has a centroidal mass moment of inertia of 0.3kg.m2 and when given an initial twist and released is found to have a frequency of oscillation of 200 rpm. Knowing that when this pendulum is immersed in oil and when given the same initial condition it is found to have a frequency of oscillation of 180 rpm, determine the damping constant for the oil.