Advertisements
Advertisements
प्रश्न
Answer the following question in your own words.
What factors are important to get a distinct echo?
Advertisements
उत्तर
- Ambient temperature and the distance between the sound source and the reflecting surface are two factors that are important in the formation of echoes.
- The speed of sound in air at 22°C is 344 m/s. Our brain retains a sound for 0.1 seconds, so only if the sound reaches the barrier and reaches the listener's ears after more than 0.1 seconds will we hear it as a separate sound.
- Distance = Speed × Time
= 344 m/sec × 0.1 sec
= 34.4 m
Thus, the distance from the source of the sound to the obstacle and back to the source is the distance that the sound must travel at least 34.4 m. - So the minimum distance from the sound source to the obstacle should be half of the above distance i.e. 17.2 meters to hear a clear echo.
- These distances are different at different temperatures.
APPEARS IN
संबंधित प्रश्न
An echo returned in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 m s−1?
What is meant by an echo?
A man is standing at a distance of 12 m from a cliff. Will he be able to hear a clear echo of his sound? Give a reason for your answer.
The minimum distance between the source and the reflector in air. So that an echo is heard is approximately equal to ______.
Explain why, the flash of lightning reaches us first and the sound of thunder is heard a little later.
Which of the following statement best describes frequency?
Name any two objects which are good reflectors of sound.
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a bare room
The frequencies of four sound waves are given below. Which of these sound waves can be used to measure the depth of sea by the echo method ?
Answer the following question in your own words.
What is an echo?
Answer the following question in your own words.
What should be the dimensions and the shape of classrooms so that no echo can be produced there?
State two conditions necessary for hearing an echo.
How can you calculate the speed of sound using echo?
When sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound remain the same. Do you hear an echo sound on a hotter day? Justify your answer.
To hear an echo, the minimum distance of the obstacle from the source of sound must be ______.
______ is an image obtained by the use of reflected ultrasonic waves.
Rohan conducted experiments on echo in different media. He observed that a minimum distance of 'x' meters is required for the echo to be heard in oxygen and 'y' meters in benzene. Compare 'x' and 'y'. Justify your answer.
Speed of sound in oxygen: 340 ms-1
Speed of sound in benzene: 200 ms-1
