sound class 8 physics

Wave Motion and Sound..

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Intensity and Loudness of Sound - Physically, a wave involves the propagation of energy. This transfer of energy by a traveling wave is expressed in terms of the intensity I. Intensity of sound waves is defined as the average energy transported per second per unit area..

At NTP., with pressure of air = P = 0.76 x 9.8 x 13.6 x 10 3 = 1.013 x 10 5 Pa or Nm - 2 Substituting these values in equation (1-26) But this value of the velocity of sound at 0 o C, is not in agreement with the experimental value which is 332ms - ..

. The larger the volume, the longer it takes for sound traveling at approximately 345 ms - 1 , to traverse the distances between the reflecting walls. When surfaces exposed to sound waves are highly absorbent, the rate of energy absorption by all surfaces quickly becomes equal t..

The velocity of electromagnetic waves is 3 x 10 8 ms - 1 . On the other hand, the velocity of sound waves cannot be used to transmit intelligence to far off places. Only electromagnetic waves can be made to do this. Modulation is extremely necessary in communication systems due ..