It is observed during an earthquake, that the short period seismic waves damage low rise buildings while long period waves damage high rise buildings.

(a) Resonance.

(b) A high rise building is tall, so its natural time period of vibration is large (i.e., its natural frequency is low). When long period seismic waves reach such a building, the time period of these waves becomes equal to the natural time period of the building. The building therefore vibrates under resonance and the amplitude of its vibration becomes very large, so the building gets damaged.