Physics
A student wishes to measure the speed of sound in air. He plans to measure the time between making the sound and hearing its echo from a cliff. What type of sound should he make and which distance should he use in his calculations ? | Sound | Distance ------|-------|--------- (a) |Continuous sound | (b) |Continuous sound | Distance to cliff x 2 (c) |Short, sharp sound | (d) |Short, sharp sound | Distance to cliff x 2 1. Option (a) 2. Option (b) 3. Option (c) 4. Option (d)
Answer
Option (d)
Reason — To measure the speed of sound using echo, the student must make a short, sharp sound so that the reflected sound (echo) can be clearly distinguished and the sound travels to the cliff and back, so the total distance travelled by the sound is 2 × the distance to the cliff.
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