Advertisements
Advertisements
प्रश्न
Sunil is standing between two walls. The wall closest to him is at a distance of 660 m. If he shouts, he hears the first echo after 4 s and another after another 2 seconds.
- What is the velocity of sound in air?
- What is the distance between the two walls?
Advertisements
उत्तर
Given - a distance of the nearest wall from Sunil = 660 m
Time after which Sunil hears first echo, (t1) = `(4 sec)/(2 sec)` = 2 s
Time after which Sunil hears second echo (t2) = `(6 sec)/(2 sec)` = 3 s
Velocity = `"distance"/"time"`
Let d1 be the distance of closest wall.
Let d2 be the distance of the other closest wall.
V = `"d"_1/"t"_1 = 660/2` = 330 m/s
Velocity = 330 m/s
Velocity = `"d"_2/"t"_2`
330 = `"d"_2/3`
330 × 3 = `"d"_2`
`"d"_2 = 990`
Distance between the two walls -
d1 + d2 = 660 + 990 = 1650 m
Distance between the two walls - 1650 m
APPEARS IN
संबंधित प्रश्न
Write true or false for a given statement.
Sound can travel in a vacuum.
Describe an experiment to show that sound can travel in water.
A boy fires a gun and another boy at a distance of 1020 m hears the sound of firing the gun 3 s after seeing its smoke. Find the speed of sound.
If you want to hear a train approaching from far away, why is it more convenient to put the ear to the track?
A jet aircraft flies at a speed of 410 m/s. What is this speed known as?
What is the time-period of a tuning fork whose frequency is 200 Hz?
A cricket ball is seen to hit the bat first and the sound of hitting is heard a little later. Why?
If the speed of a wave is 340 m/s and its frequency is 1700 Hz, then λ for this wave in cm will be :
A man is kidnapped, blindfolded and imprisoned in a big room. How could the man tell if he was in : a village
The drawing shows a ship 800 m from a cliff. A gun is fixed on the ship. After 5 seconds the people at the front of the ship hear the sound of the gun again.
(a) What is the name of this effect ?
(b) What happens to the sound at the cliff ?
(c) How far does the sound travel in 5 seconds ?
(d) Calculate the speed of sound.
Hydrogen gas is filled in two identical bottles, A and B, at the same temperature. The mass of hydrogen in the two bottles is 12 gm and 48 gm respectively. In which bottle will sound travel faster? How many times be as fast as the other?
The velocity of sound in air at a particular temperature is 330 ms–1. What will be its value when temperature is doubled and the pressure is halved?
A source of sound is travelling with a velocity 40 km/h towards an observer and emits a sound of frequency 2000 Hz. If the velocity of sound is 1220 km/h, then the apparent frequency heard by the observer is _____.
The velocity of sound is independent of temperature.
Air temperature in the Rajasthan desert can reach 46°C. What is the velocity of sound in air at that temperature? (V0= 331 ms–1)
A strong sound signal is sent from a ship towards the bottom of the sea. It is received back after 1s. What is the depth of sea given that the speed of sound in water 1450 ms–1?
Establish the relationship between the speed of sound, its wavelength and frequency. If the velocity of sound in air is 340 m s–1, calculate
(i) wavelength when the frequency is 256 Hz.
(ii) frequency when the wavelength is 0.85 m
Sound travels faster in ______ and slower in ______.
Numerical problems:
Two persons are at opposite ends of a steel rod. One strikes the end of the rod with a stone. Find the ratio of time taken by the sound wave in the air and in steel to reach the second person. (Sound of speed in steel = 5960 ms-1, Sound of speed in air = 344 ms-1).
