Q$3($a$)$ A spring$-$mass$-$dashpot system is excited by a harmonic force. At

resonance, the amplitude is measured to be $0\mathrm{.}6$ cm $.$ At $0\mathrm{.}80$ resonant

frequency, the amplitude is measured to be $0\mathrm{.}5$ cm $.$ Determine the

damping factor $$ of the system.