Advertisements
Advertisements
प्रश्न
The wavelength of waves produces on the surface of water is 20 cm. If the wave velocity is 24 m s-1, calculate:
- the number of waves produced in one second, and
- the time in which one wave is produced.
उत्तर
(i) Frequency or the number of waves produced per second
= `"Velocity"/"Wavelength"`
= `24/(20 × 10^-2`
= 120 Hz
(ii) Time = `1/ "frequency"`
= `1/120`
= 8.3 × 10-3 seconds
APPEARS IN
संबंधित प्रश्न
Calculate the minimum distance in air required between the source of sound and the obstacle to hear an echo. Take speed of sound in air = 350 m s-1
A man standing 48 m away from a wall fires a gun. Calculate the time after which an echo is heard. (The speed of sound in air is 320 ms-1).
A sound made on the surface of a lake takes 3 s to reach a boatman. How much time will it take to reach a diver inside the water at the same depth?
Velocity of sound in air = 330 ms−1
Velocity of sound in water = 1450 ms−1
A person fires a gun while standing at a distance of 850 m from a building. If the speed of sound is 350 ms, calculate the time in which the person hears an echo of the gun flte.
A ship which is stationary at a distance of 680 m from the shore, sends a signal to the coast. Its echo is heard in 4s. Find the velocity of sound.
An observer stands at a distance of 850 m from a cliff and fires a gun. After what time gap will he hear the echo? If sound travels at a speed of 350 m/sec., in air.
The wavelength and frequency of the sound wave in a certain medium is 40 cm and 835 Hz respectively. In the same medium if another wave has a wavelength equal to 32 cm, calculate its frequency.
A man standing between two cliffs produces a sound and hears two successive echoes at intervals of 3s and 4s respectively. Calculate the distance between the two cliffs. The speed of sound in the air is 330 ms−1.
A boy stands in from of a cliff on the other side of a river. He fires a gun and hears an echo after 6 seconds. The boy then moves backward by 170 m and again fires the gun. He hears an echo after 7 seconds. Calculate
(i) width of river,
(ii) speed of sound.
A person standing between two vertical cliffs and is 640 m away from the nearest cliff. He shouted and heard the first echo after 45s and the second echo after further 3s. Calculate the speed of sound in air and the distance between the cliffs.
