A tuned mass damper is used to dampen the vibrations of a larger mass ) connected to a fixed support, usually the ground, via a spring with stiffness using a relatively much smaller mass ). The smaller tuning mass is connected in series to the larger mass via a spring with stiffness and a dashpot with viscosiity . Carefully choosing the connecting spring and dashpot gives a system that rapidly attenuates the motion of the larger mass. In this demonstration, try to choose combinations of masses (ratios of ), combinations of spring stiffnesses (ratios of ), and dashpot viscosity ratio ) to get the best attenuation. You can run, pause, and reset the initial conditions of the system at any time.