"Soldiers are not allowed to march on a bridge". Give reason.

1.	"Soldiers are not allowed to march on a bridge". Give reason.
Answer» Solution :While crossing a bridge, if the PERIOD of stepping on the ground by marching soldiers be equal to the NATURAL frequency of the bridge, it may be thrown into RESONANCE vibration and the VIBRATIONS may be so large that the bridge may COLLAPSE. Thus to avoid resonant vibration of the bridge. Soldiers are ordered to break steps

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