https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5 PHYSICS STANDARD IX CHAPTER 7 en-us 2024-02-23 07:12:43 UTC 2024-02-25 09:27:26 UTC hello@padlet.com karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894657528 1. Introduction 
2. Wave motion 
3. Mechanical waves 
4. Characteristics of waves 
5. Sound 
6. Reflection of sound 
7. Multiple reflection of sound 
8. Situations making use of multiple reflection 
9. Reverberation 
10. Echo 
11. Acoustics of buildings 
12. Ultrasonic sound 
13. Uses of ultrasonic waves 
14. SONAR 
15. Seismic waves 
16. Tsunami 
17. Let us assess
18. Concept map
19 . References 

]]> 2024-02-25 05:03:35 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894657528 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894661301 After placing a paper boat in the pond the child is continuously making ripples in the water to push it away from the shore. But the boat moves only up and down and it doesn't move forward. What may be the reason ?

You might have seen ripples formed in  water when a stone is dropped into it. How does the disturbance produced by the stone in water spread to other areas? Doesn't it spread like expanding concentric circles? Let's find out ]]> 2024-02-25 05:17:11 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894661301 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894664642 Wave motion is the propagation of disturbances produced in one part of a medium to the other parts by the vibration of its particles. It is one of the means to transfer energy from one region of the medium to another. In a wave motion the energy received from one particle is transferred from particle to particle thus spreading all over 


]]> 2024-02-25 05:33:08 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894664642 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894666850 2024-02-25 05:43:22 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894666850 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894668632 The waves which need a medium for their propogation are called mechanical waves. There are mainly two types of mechanical waves 

. Transverse wave 
. Longitudinal wave ]]> 2024-02-25 05:51:46 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894668632 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894670055 A transverse wave is a wave in which the particles of the medium vibrate in a direction perpendicular to the direction of the propogation of wave ]]> 2024-02-25 05:58:52 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894670055 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894672109 A longitudinal wave is a wave in which the particles of the medium vibrate in a direction parallel to the direction of propogation of the wave. This creates compressions and refractions alternately in the medium ]]> 2024-02-25 06:08:10 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894672109 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894672641 Compression is that part of the longitudinal wave in which the medium of particles are closer and there is momentary decrease in volume of medium. Rarefaction is that part of longitudinal wave in which the medium of particles are apart and there is momentary increase in volume of medium.]]> 2024-02-25 06:10:29 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894672641 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894675567 2024-02-25 06:23:39 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894675567 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894678225 Amplitude is the maximum displacement of a particle from its mean position ]]> 2024-02-25 06:35:55 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894678225 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894678452 The table shows that speed of sound is different in different media.]]> 2024-02-25 06:36:51 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894678452 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894679191 Wavelength is the distance advanced by the wave by the time a particle completes the vibration. This is equivalent to the distance between two consecutive particles which are in the same phase of vibration. The Greek letter λ (lambda) is used to denote wavelength. The unit of wavelength is metre (m).]]> 2024-02-25 06:39:55 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894679191 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894680145 Period of a wave is the time taken for a particle in a medium to make one complete vibration. This is represented by the letter T. The unit of period is second (s)]]> 2024-02-25 06:43:52 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894680145 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894681292 Frequency is the number of vibrations in one second 

Frequency(f)= ( Number of vibrations)/ ( Timetaken)

If frequency and period are interrelated we can write it down as 
                      f = 1/T 

The unit of frequency is hertz (Hz)
   
   ]]> 2024-02-25 06:48:11 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894681292 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894682429 The speed of a wave is the distance travelled by the wave in one second.

The equation for finding speed is 

Speed = distance/ time 

Wavelength (λ) is the distance travelled by a wave in a time of one period (T)
so, 
speed of wave= λ/T

v= (1/T)*λ

v= fλ

The unit of speed is m/s]]> 2024-02-25 06:52:13 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894682429 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894683646 Sound is produced by vibrating objects. A medium is essential for the propogation of sound. Sound coming from a source produces continuous variations in the pressure on a medium. So a series of compressions and rarefactions is created in the air and these make sound waves propogate through the medium ]]> 2024-02-25 06:56:53 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894683646 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894685489 Sound gets reflected very well from smooth surfaces]]> 2024-02-25 07:04:18 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894685489 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894687232 Sound getting reflected repeatedly from different objects is multiple reflection ]]> 2024-02-25 07:10:03 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894687232 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894692699 Devices like megaphones, horns musical instruments like shehanai and trumpets are made in such way that sound produced from them travels in a certain direction only without spreading to other directions.]]> 2024-02-25 07:31:07 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894692699 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894694908 2024-02-25 07:38:42 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894694908 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894695090 The ceilings of halls are given a curvature]]> 2024-02-25 07:39:15 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894695090 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894696104 The curved sound boards placed behind the screen makes the sound undergo multiple reflections and spreads everywhere in the hall.]]> 2024-02-25 07:42:38 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894696104 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894696494 Reverberation is the persistence of sound as a result of multiple reflection ]]> 2024-02-25 07:44:10 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894696494 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894697795 Echo is the phenomenon of hearing a sound by reflection from a surface or obstacle, after hearing the original sound ]]> 2024-02-25 07:48:34 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894697795 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894700296 Acoustics of buildings is the branch of science that deals with the conditions to be fulfilled in the construction of a building for clear audibility]]> 2024-02-25 07:56:28 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894700296 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894703115 Sound with a frequency greater than 20000Hz, ie, above the higher limit of audibility is called ultrasonic sound]]> 2024-02-25 08:05:55 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894703115 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894711547 2024-02-25 08:35:52 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894711547 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894712063 2024-02-25 08:37:22 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894712063 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894713147 2024-02-25 08:40:47 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894713147 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894714625 2024-02-25 08:45:50 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894714625 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894726288 2024-02-25 09:20:01 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894726288 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894727890 2024-02-25 09:24:58 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894727890 karthikrbabu8 https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894728745 https://books.google.co.in/books/about/Vibrations_and_Waves.html?id=JDsPEAAAQBAJ&redir_esc=y#v=onepage&q&f=false
https://www.bookswagon.com/book/waves-mike-freelance-acoustician-goldsmith/9780198803782]]> 2024-02-25 09:27:26 UTC https://padlet.com/karthikrbabu8/llqx4x5h5dol1sn5/wish/2894728745