Why are soldiers ordered to move out of step while crossing a bridge?

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

Every oscillator has its own frequency of oscillation.  When frequency of external force becomes equal to natural frequency of oscillations, resonance takes place and amplitude of vibration becomes maximum.  Bridge can be considered as stretched string.  If soldiers march in steps and frequency of marching steps is the same as that of frequency of bridge, then bridge will be set into resonant vibrations and hence collapse.  That is why soldiers are asked to break their steps.

Answered by  | 4th Jun, 2014, 03:23: PM