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प्रश्न
When a troop crosses a suspension bridge, the soldiers are asked to break steps. Explain the reason.
When a troop crosses a suspension bridge, the soldiers are asked to break their steps. Why?
उत्तर
When a troop crosses a suspension bridge, the soldiers are asked to break steps. The reason is that when soldiers march in steps, all the separate periodic forces exerted by them are in same phase and therefore forced vibrations of a particular frequency are produced in the bridge. Now, if the natural frequency of the bridge happens to be equal to the frequency of the steps, the bridge will vibrate with large amplitude due to resonance and suspension bridge could crumble.
संबंधित प्रश्न
Give one example to illustrate forced vibrations.
In fig. , P, Q, R and S represent test tubes each of height 20 cm which are filled with water upto heights of 10 cm, 14 cm, 16 cm and 18 cm respectively. If a vibrating tuning fork is placed over the mouth of test tube Q, a loud sound is heard.
(i) Describe the observations with the tubes P, R and S.
(ii) Give the reason for your observation in each case.
(iii) State the principle illustrated by the above experiment.
In fig. shows two tuning forks P and Q of the same frequency mounted on separate sound boxes with their open ends facing each other. The fork A is set into vibration. (i) Describe your observation. (ii) State the principle illustrated by this experiment.
Give two examples of forced vibrations.
Explain Why are stringed musical instruments provided with large sound boxes?
What do you understand by forced vibrations?
Explain free and forced vibrations. Give an experimental arrangement to illustrate the phenomenon of resonance.
