मराठी
महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (मराठी सेमी-इंग्रजी) इयत्ता ९ वी

Sunil is standing between two walls. The wall closest to him is at a distance of 360 m. If he shouts, he hears the first echo after 4 s and another after another 2 seconds. - Science and Technology

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.

  1. What is the velocity of sound in air?
  2. What is the distance between the two walls? 
बेरीज
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 -

d+ d= 660 + 990 = 1650 m

Distance between the two walls - 1650 m

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 12: Study of Sound - Exercise [पृष्ठ १३७]

APPEARS IN

बालभारती Science and Technology [English] 9 Standard Maharashtra State Board
पाठ 12 Study of Sound
Exercise | Q 5. c. | पृष्ठ १३७

संबंधित प्रश्‍न

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Given, g = 10 m s−2 and speed of sound = 340 m s−1.


Fill in the blank.

Sound travels faster in ________ than in liquids.


Describe an experiment to show that sound can travel in water.


Write the approximate speed of sound in steel.


Calculate the speed of a sound wave whose frequency is 2 kHz and wavelength 65 cm.


A sound signal of 128 vibrations per second has a wavelength of 2.7 m. Calculate the speed with which the wave travels.


A worker lives at a distance of 1.32 km from the factory. If the speed of sound in air be 330 m/s, how much time will the sound of factory siren take to reach the worker?


A worker lives at a distance of 1.32 km from the factory. If the speed of sound in air be 330 m/s, how much time will the sound of factory siren take to reach the worker?


Fill in the blanks with suitable words .

Wave speed in metres per second equals frequency in ............ multiplied by ..................... in ..................


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?


Why does the flash of lighting reach earlier than the sound of thunder?


The Velocity of sound is high in gases than liquids.


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)


Sound travels faster in ______ and slower in ______.


Assertion: The speed of sound in air is less than the speed of sound in solid.
Reason: If we increase the temperature of medium, the speed of sound increases in any medium.


The speed of sound in a gaseous medium depends on the nature of the gas.


On which factors does the speed of sound in the gaseous medium depend?


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).


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×