: In order to measure the body mass of an astronaut in space, a special chair attached to springs is used. The frequency of the oscillation of the astronaut is measured and from this, the mass is computed. Suppose that the chair has been calibrated as follows: the chair itself has mass of 20kg and an additional 25kg is placed in the chair. The resulting oscillation has period of 1.30 seconds. What is the mass of an astronaut if the period of oscillation is 1.75 seconds