Exercise class 9 science chapter 12 study of sound । Exercise study of sound । Question answer std 9

• Exercise 9th Science    / @alltrends-n2r   Exercise class 9 science chapter 12 study of sound, Exercise study of sound, Question answer std 9, Question answer study of sound, Fill in the blanks and explain. a. Sound does not travel through ………… b The velocity of sound in steel is …............ than the velocity of sand in water. c. The incidence of ……… in daily life shows that the velocity of sound is less than the velocity of light. d. To discover a sunken ship or objects deep inside the sea, ....................... technology is used. 2. Explain giving scientific reasons. a. The roof of a movie theatre and a conference hall is curved. b. The intensity of reverberation is higher in a closed and empty house. c. We cannot hear the echo produced in a classroom. 3. Answer the following questions in your own words. a. What is an echo? What factors are important to get a distinct echo? b. Study the construction of the Golghumat at Vijapur and discuss the reasons for the multiple echoes produced there. c. What should be the dimensions and the shape of classrooms so that no echo can be produced there? 4. Where and why are sound absorbing materials used? 5. Solve the following examples. a. The speed of sound in air at 0 0 C is 332 m/s. If it increases at the rate of 0.6 m/s per degree, what will be the temperature when the velocity has increased to 344 m/s? (Ans: 200 0 C) b. Nita heard the sound of lightning after 4 seconds of seeing it. What was the distance of the lightning from her? (The velocity of sound in air is 340 m/s?) (Ans: 1360 m) c. Sunil is standing between two parallel 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? (Ans: 330 m/s; 1650 m) d. 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 may times as fast as the other? (Ans: In A; Twice) e. Helium gas is filled in two identical bottles A and B. The mass of the gas in the two bottles is 10 gm and 40 gm respectively. If the speed of sound is the same in both bottles, what conclusions will you draw? (Ans: Temperature of B is 4 times the temperature of A.) Project : Collect information about the musical instrument called Jaltarang and find out how the different notes are produced in it. Exercises Exercise class 9 science chapter 12 study of sound, Exercise study of sound, Question answer std 9, Question answer study of sound, Fill in the blanks and explain. a. Sound does not travel through ………… b The velocity of sound in steel is …............ than the velocity of sand in water. c. The incidence of ……… in daily life shows that the velocity of sound is less than the velocity of light. d. To discover a sunken ship or objects deep inside the sea, ....................... technology is used. 2. Explain giving scientific reasons. a. The roof of a movie theatre and a conference hall is curved. b. The intensity of reverberation is higher in a closed and empty house. c. We cannot hear the echo produced in a classroom. 3. Answer the following questions in your own words. a. What is an echo? What factors are important to get a distinct echo? b. Study the construction of the Golghumat at Vijapur and discuss the reasons for the multiple echoes produced there. c. What should be the dimensions and the shape of classrooms so that no echo can be produced there? 4. Where and why are sound absorbing materials used? 5. Solve the following examples. a. The speed of sound in air at 0 0 C is 332 m/s. If it increases at the rate of 0.6 m/s per degree, what will be the temperature when the velocity has increased to 344 m/s? (Ans: 200 0 C) b. Nita heard the sound of lightning after 4 seconds of seeing it. What was the distance of the lightning from her? (The velocity of sound in air is 340 m/s?) (Ans: 1360 m) c. Sunil is standing between two parallel 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? (Ans: 330 m/s; 1650 m) d. 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 may times as fast as the other? (Ans: In A; Twice) e. Helium gas is filled in two identical bottles A and B.