Final answer:
Buildings are over damped to prevent excessive oscillations and return to their starting position quickly, using devices like tuned-mass dampers to mitigate resonance issues during events like earthquakes.
Step-by-step explanation:
Buildings are prevented from resonating with the purity of a pendulum because they are over damped, meaning they are inefficient in their vibration and, when set in motion, tend to return to their starting position quickly without oscillating excessively. As buildings, such as the Comcast Building, are built taller and act like inverted physical pendulums, tuned-mass dampers like a tuned, liquid-column mass damper can be used to reduce oscillations. These dampers contain a reservoir of water that oscillates freely at a frequency matching the building's natural frequency, with turbulence levels controlled by baffles to provide damping. This is crucial during events like earthquakes, where resonant frequencies can cause buildings to collapse due to amplified oscillations from standing waves and constructive interference. However, over damping helps to ensure that the energy from such disruptions is dissipated quickly, mitigating potential resonance issues and ensuring the structural integrity of the building.