Q 4) (15 marks) The pipe carrying feed-water to a boiler in a thermal power plant has been found to vibrate violently at a pump speed of 800 rpm. In order to reduce this high vibration level, an absorber consisting of a spring of stiffness k, and a trial mass of I kg is attached to the pipe. This arrangement is found to give natural frequencies of the system at 750 rpm and 1000 rpm. Design the absorber to be attached to the pipe, i.e. calculating the values of the mass m,and stiffness k,, to keep the natural frequencies of the system outside the operating range of the pump; which is 700 rpm to 1040 rpm. For practical motivations, don't use the frequency ratio