When A Troop Crosses A Suspension Bridge The Soliders Are Asked To Break Step

When a troop crosses a suspension bridge, the soliders are asked to break step. Explain.


The reason is that when soldiers are in steps, they all exert forces in the same phase and so strong vibrations of a particular frequency are produced. If this frequency becomes equal to the natural frequency of the bridge, it will start vibrating with large amplitude due to resonance and it may crumble down.