earthquake

[msjl33]

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A building in an earthquake sway back and forth with gradually increasing amplitude until a collapse finally occurs. This is an example of:
a) destructive interference
b)the Doppler effect
c) resonance
d) Young's modulus.


answer is (c).


I get why it's not b and d. I thought it would be a, but why resonance?!?!?!?

 

[Rabolisk]

If you had destructive interference, you wouldn't get this building up of amplitude and collapse. The waves would destruct out to nada. An example of resonance is glasses breaking when one sings loudly and at the right frequency. The frequency from the external source matches the resonant frequency of the glass, producing a huge amplitude, and eventually destruction.

 

[fizzgig]

just as another example, it's like pushing a kid on a swing. you need to be pushing (adding energy) at the right frequency to get the kid to continually go higher, til he eventually flies out.