An air compressor of mass \(200 \mathrm{~kg}\), with an unbalance of \(0.01 \mathrm{~kg}-\mathrm{m}\), is found to have a large amplitude of vibration while running at \(1200 \mathrm{rpm}\). Determine the mass and spring constant of the absorber to be added if the natural frequencies of the system are to be at least 20 percent from the impressed frequency.