Sound Worksheet-12

Sound Worksheet-12

71. What is sonar? Explain its use.

72. A sonar station picks up a return signal after 3 seconds. How far away is the object?

(Speed of sound in water = 1440 m/s).

73. Draw a neat and labelled diagram of the human ear. With the help of this diagram, explain the construction and working of the human ear.

74. The drawing shows a ship 800 m from a cliff. A gun is fired on the ship. After 5 seconds the people at the front of the ship hear the sound of the gun again.

(a) Write the name of this effect?

(b) What happens to the sound at the cliff?

(c) The distance traveled by sound 5 seconds?

(d) What is the speed of sound?

75. Consider the following sound waves marked A, B, C and D:

Which two waves represent sounds of the same loudness but different pitch?

76. Consider the following sound waves marked A, B, C and D:

Which two waves represent sounds of the same frequency but different loudness     

77. Consider the following sound waves marked A, B, C and D:

State whether all these sound  waves  have  been produced by the same vibrating  body or different vibrating bodies

78. Consider the following sound waves marked A, B, C and D:

Which vibrating body/bodies could have generated the sound waves shown here          

79. In an experiment, Arun studies sound waves. He sets up a loudspeaker to produce sound as shown below:

Anhad adjusts the signal to the loudspeaker to give a sound of frequency 200 Hz.

What happens to the air in-between Anhad and the loudspeaker? Explain how Arun receives sound in both ears.

80. Figure X shows a trace of a sound wave produced by a particular tuning fork :

(a)    On the graph paper given in Figure Y, draw a trace of the sound wave which has a higher frequency than that shown in Figure X.

(b)    On the graph paper shown in Figure Z, draw a trace of the sound wave which has a larger amplitude than that shown in Figure X.

81. Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

What type of sounds are (i) X, (ii) Y, and (iii) Z?

82. Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

Name one device which can produce sound like X.

83. Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

Name one device in a science laboratory which can produce sound like Y.

84. Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

Name one device in our homes which can produce sound like Z.

85. Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains which then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

What is the frequency range of sounds like Z?

Answer:

71. –

72. 2160 m

73. –

74. (a) Echo, (b) Sound gets reflected, (c) 1600 m, (d) 320 m/s

75.  A and D

76. B and D

77.  Same vibrating body

78. Tuning forks

79. The air in-between Arun and the loudspeaker vibrates with the frequency of 200 Hz

Arun receives sound in the right ear by the sound waves coming directly from the loudspeaker (through air); Arun receives sound in the left ear from sound waves reflected from the wall of classroom.

81. Ultrasonic sound  (ii) Infrasonic sound  (ii) Audible sound (Ordinary sound)

82. Ultrasound machine in hospitals

83.  Simple pendulum

84.  Radio

85. 20 Hz to 20000 Hz