A fragile instrument and its housing, which together weigh 10 lbs, are mounted on four symmetrically located identical springs as a means of isolating the instrument from the vibration of

the table supporting it. Measurements indicate that the table reaches a maximum amplitude of 0.004 inch somewhere in the frequency range of 20 to 30 Hz.Determine the spring constant k of each spring so that the amplitude of vibration of the instrument will be limited to 0.0002 inch as a maximum.