Explain the natural frequency of vibration in a mass-spring system.

Select the right answer for each of the following: 1- The damped vibrational system is. system, (c) none of these, (d) false statement. (a) conservative system, (b) nonconservative (a) viscous (b) solid 2- When a system vibrates in a fluid medium, the damping is (c) Coulomb. 3- When an initial excitation exerted on a vibrational system results in - ippearance. (a) natural frequency. (b) resonance. (c) beating. (d) none of these. 4- Undamped vibration is characterized by no loss of 1) (a) speed, (b) acceleration, (c) mass, (d) energy. (a) mass, (b) damper, 5- Vibratory system should at least consists of a spring and - (c) mass and damper.

The amplitude of vibration of a single degree of freedom spring-mass-damper system is observed to reduce to 15 % of its initial value after 5 cycles. Spring stiffness equals (1500 + 007) N/m and mass equals (7.5 + 007) kg. Determine: The undamped natural frequency; The damped natural frequency; The logarithmic decrement; The damping ratio; and The coefficient of damping.