42 solutions available
Question 1A 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...
Question 2A boy on a hill A fires a gun. Another boy on hill B hears the sound after 4 s. If the speed of sound is 330 m s-1, find the distance...
Question 3Match the following:Column AColumn B(a) Vibrations cause(i) absorb sound(b) A shriller sound is(ii) second(c) Unit of frequency(iii)...
Question 4bWe can hear sound of frequency:10 Hz500 Hz100,000 Hz50,000 Hz
Question 4cSound cannot travel in:gasesliquidssolidsvacuum
Question 4dThe minimum distance required between the source and the reflector so as to hear the echo in air is:10 m17 m34 m50 m
Question 4Describe an experiment to show that each source of sound is a vibrating body.
Question 8Can sound travel through a vacuum? Describe an experiment to explain your answer.
Question 9Describe an experiment to show that sound can travel in water.
Question 10Describe an experiment to show that sound can travel in a solid.
Question 11Can two persons hear each other on moon's surface? Give reason to support your answer.
Question 12What is a longitudinal wave?
Question 13Define the following terms:AmplitudeTime periodFrequency
Question 14Write the audible range of frequency for the normal human ear.
Question 15What are ultrasonics? Can you hear the ultrasonic sound?
Question 16What are infrasonics? Can you hear them?
Question 17How does a bat make use of ultrasonic waves to find its way?
Question 18Name the two characteristics of sound which differentiate any two sounds from each other.
Question 19On what factor does the loudness of a sound depend?
Question 20How does the loudness of sound produced depend on the vibrating area of the body?
Question 21The outer case of the bell in a temple is made big. Give a reason.
Question 22State the factors on which the pitch of a sound depend?
Question 23Differentiate between a high pitch sound and a low pitch sound.
Question 24How does a man's voice differ from a woman's voice?
Question 25Name the characteristic which differentiates two sounds of the same pitch and same loudness.
Question 26You recognize your friend by hearing his voice on a telephone. Explain.
Question 27A musician recognizes the musical instrument by hearing the sound produced by it, even without seeing the instrument. Which characteristic...
Question 28Describe an experiment to show the production of sound having low and high pitch.
Question 29How does a musician playing on a flute change the pitch of sound produced by it?
Question 30Why are musical instruments provided with more than one string?
Question 31How can the pitch of sound produced in a piano be changed?
Question 32Explain why you can predict the arrival of a train by placing your ear on the rails without seeing it.
Question 33Write the approximate speed of sound in:(i) air(ii) water(iii) steel
Question 34During a thunderstorm, the sound of a thunder is heard after the lightning is seen. Why?
Question 35Describe an experiment to estimate the speed of sound in air.
Question 36Can sound travel through solids and liquids? In which of these two does it travel faster?
Question 37What do you mean by reflection of sound?
Question 38State one use of reflection of sound.
Question 39What is an echo?
Question 40What minimum distance is required between the source of sound and the reflecting surface to hear an echo? Give reason.
Question 41List four substances which are good absorbers of sound.
Question 42List the measures that you will take when designing a sound-proof room.