Question 3 [10 marks] A large machine has a mass of
200kg
and is mounted on an undamped elastic foundation of stiffness keq as shown. During operation at
110ra(d)/(s)
, the machine is subject to a harmonic force of magnitude
2200N
; a) Determine the required stiffness
k
of an undamped vibration absorber of mass
20kg
such that steady-state vibrations of the machine are eliminated during operation. b) When this absorber is used, what is the frequency range such that the machine's steady state amplitude is less than
1.3mm
?