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Grade 12th passWave Motion

Figure given has a sinusoidal wave on a string.If the frequency is 150Hz and the mass per unit length is 0.2g/m the pweor transmitted by the wave is?
(A) 2.34 W (B) 3.84W (C) 4.80 W (D) 5.78 W

Question image for Figure given has a sinusoidal wave on a string.If
Profile image of Faiz Anwar
8 Years agoGrade 12th pass
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1 Answer

Profile image of Sanghamitra Chatterjee
7 Years ago
According to the figure,
5\lambda/2= 20 cm (where \lambda=wavelength) 
So,  \lambda= 8 cm=0.08 m
Mass per unit length of the string (\mu)= 0.2 g/m =0.0002 kg/m
Frequency (f) =150 Hz
Wave speed (v) =\lambda*f= 0.08*150=12 m/s
\omega=2πf=2*3.14*150
Amplitude of wave (A) = 0.06 m
Average  power transmitted  by a wave
=(1/2)*\mu*v*(\omega^2)*(A^2)
=3.83341248 W
Approximately = 3.84 W