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SOUND final.pptx
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- 2. ● What wasthat? ● Can everyone hear that? ● From where it was generated? ● Name other instruments which produces such type of sounds?
- 3. ● Do allthe instruments can produce same type of sound? ● Which organ helps us to produce sound and which organ is needed to receive the sound? ?
- 4. Sound is producedby vibration ● What is vibration? quickly moving back and forth (or up and down) about a point of equilibrium.
- 5. Have you ever noticedthis? What is happening here?
- 6. Where do youfind these things?
- 7. ACTIVITY 1 Takea metal plate and hang it from a hook. Strike the plate with a stick and place your finger on the plate gently after striking. Then what will you see? Now touch the plate when you have not stroke it with a stick. Can you feel the vibration now?
- 8. ACTIVITY 2 Put rubberband inside 2 pencils and stitch the band like this figure. Now pluck the rubber band at any point. Can you hear the sound? Does the band vibrates?
- 9. Look at theother instruments that also can produce sound and they are commonly used in various parts of India.
- 10. Jaltarang The different heightsof water produces different types of sound
- 11. Sound produced byhumans
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- 13. Activity Look at theimages and try to understand what they are doing
- 14. Why voices ofmen, women and child are different?
- 15. Why voices ofmen, women and child are different?
- 16. Propagation of sound: ● Medium is always required for sound propagation. ● The sound travel by vibration of medium molecules. ● The speed of sound is maximum in solids, minimum in gases.
- 18. Can any onehear the voice of the astronaut?
- 19. Sound is beingpropagated through different mediums.
- 21. ● Sound cantravel through 1. Gases only 2. Solids only 3. Liquids only 4. All of the above. ● Sound cannot travel in vacuum.(true/false) ● In which medium the sound travels faster? ● Identify the part which vibrates to produce sound in the following instruments. Dholak, Sitar, Flute.
- 22. used for guidingliquid or powder into a small opening. What are these?
- 23. How do wehear sounds : ● Through this 👂
- 24. How do wehear sounds : ● Through this ● Sound enters the funnel like ear and travel through a canal and hits eardrums 👂
- 25. How do wehear sounds : ● Through this ● Sound enters the funnel like ear and travel through a canal and hits eardrums ● Eardrums: a thin membrane streached tightly at the end of the ear 👂
- 26. ● Eardrum islike a stretched rubber sheet so the incoming sound makes it vibrate. ● And the sense of vibration of eardrum goes to brain and as a result we can listen.
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- 28. What will happenif the eardrum is damaged? 🤔
- 29. What will happenif the eardrum is damaged? 🤔 ● So, don't put any sharp, hard, pointed object into ear. ● Always take the advice of doctors.
- 30. Amplitude, time period,frequency of vibration. What is vibration?
- 31. Amplitude, time period,frequency of vibration. What is vibration? ● To and fro motion of particles or objects about their mean position.
- 32. What is vibration? Amplitude,time period, frequency of vibration. ● To and fro motion of particles or objects about their mean position. ● This motion is also called oscillatory motion
- 33. Time period ● Timetaken by particle to complete one oscillation. Frequency ● The number of oscillations per second. ● Frequency is expressed in hertz(Hz) ● A frequency of 1 Hz is one oscillation per second.
- 34. ● If anobject oscillates 20 times per second then what will be its frequency? ● Time taken by an object to complete one oscillation is called____________. ● A pendulum oscillates 40 times in 4 seconds. Find out its time period and frequency.
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- 36. How much thedistance the thermocol ba goes away is the amplitude.
- 37. How much thedistance the thermocol ba goes away is the amplitude. So, AMPLITUDE is the maximum displacement of vibrating particle about its mean position.
- 38. The amplitude ofvibration signifies the loudness. • When the amplitude of vibration is large, produced sound is louder. • Loudness of sound is proportional to the square of amplitude • If the amplitude becomes thrice then how many times the loudness will increase? Loudness is expressed in decibel (dB)
- 39. Here are someideas about loudness with differentsounds. In the abouve image if the loudness is same then what differs these students.
- 40. Voice ofwhich of the following is likely to have minimum frequency? A. Baby girl B. Baby boy C. A man. C. A woman If the amplitude of vibration is large , sound is feeble . (true / false) Your parents are going to buy a house. They have been offered one on the roadside and the other is three lanes away from roadside. Which house should be better according to you?
- 41. Audible and Inaudiblesounds Can we hear sounds from all vibrating body?
- 42. Audible and Inaudiblesounds Can we hear sounds from all vibrating body? NO
- 43. Audible and Inaudiblesounds Can we hear sounds from all vibrating body? NO We can only detect 20Hz to 20000Hz vibrations per second But some other animals can hear beyond this range or below this range.
- 45. Dogs also can hear soundsof higher frequency Earthquake has very low frequency so that the animals like cow, cat, birds can listen before we feel.
- 46. Noise and Music •Do you enjoy all type of sounds?
- 47. Noise and Music •Do you enjoy all type of sounds? • Do you enjoy the sound from horns of buses, cars?
- 48. Noise and Music •Do you enjoy all type of sounds? • Do you enjoy the sound from horns of buses, cars? So, the unpleasant sounds are noises. If a pleasant sound becomes too loud then would it remains pleasant?
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- 51. 1. List someexamples which are sources of noise Pollution. And what are the measures to be taken to reduce noise Pollution. 2. What are the harmful sides of noise Pollution?