A vibrometer used to measure the amplitude of vibrations consists essentially of a box con...

A vibrometer used to measure the amplitude of vibrations consists essentially of a box containing a mass-spring system with a known natural frequency of 120 Hz. The box is rigidly attached to a surface which is moving according to the equation y = δm sin ωft.If the amplitude zmof the motion of the mass relative to the box is used as a measure of the amplitude δm of the vibration of the surface, determine (a) the percent error when the frequency of the vibration is 600 Hz, (b) the frequency at which the error is zero.

Fig. P19.121