The instrument shown has a mass of 58 kg and is spring-mounted to the horizontal base. If the amplitude of vertical vibration of the base is 0.19 mm, calculate the range of frequencies fr of the base vibration which must be prohibited if the amplitude of vertical vibration of the instrument is not to exceed 0.38 mm. Each of the four identical springs has a stiffness of 6.98 kN/m. XB Answer: fn i Hz and fn i Hz