Same chapter3 marksDifficulty: Medium
A ship sends a sound signal towards the sea bed and receives the echo after 3 s. If the speed of sound in sea water is 1500 m s−1, find the depth of the sea.
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3 marksDifficulty: Medium
Distinguish between natural, damped and forced vibrations.
Original Khojo Papers practice question — not from a past board paper.
Answer
Natural vibrations are those a body makes on its own, at its own frequency, once disturbed and then left alone, with no loss of energy. Damped vibrations are natural vibrations whose amplitude falls with time because energy is lost against friction and to the surroundings. Forced vibrations are those a body makes under a periodic force applied from outside, at the frequency of that force rather than its own.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
When the forcing frequency happens to equal the natural frequency, forced vibration becomes resonance.
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